IPAC’22

Student Poster Session Guide

Synchrotron Light Research Institute(Public Organization)

IPAC’22

Student Poster Session
Hours & Location
Sunday, June 12: 14:00 to 18:00 (setup: 13:30 – 14:00)•

The student poster session will be held on Sunday, June 12 at Main Foyer, in front of Grand Diamond Ballroom.

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Posters should be set up at 13:30–14:00.

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Students should present at their posters for presentation and interaction with judges and arrived conference delegatesat 14:00–18:00.

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All students presenting a poster at the conference are encouraged to present their work in this session.

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All students receiving grants to attend the conference must present their works in this session and must submit
contribution to the proceedings.

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Student posters are presented twice during the conference, once during the student poster session, and once during
the standard poster sessions.

Prizes & Judging•

The student poster session is separate from the main poster session and is an opportunity to showcase your work.
During the student poster session, posters will be evaluated for the Student Poster Prize by members of the IPAC’22
SPC, OC, and LOC. All students should attend their posters for interactions with judges and arriving conferencedelegates between 14:00 – 18:00.

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The evaluation committee will judge and decide the winners of two conference prizes for the best student
posters, which will be awarded US $500. Main criteria for the best poster selection are presentation and clarity,
the student’s contribution, and scientific and technical merit. The prizes will be presented during the IPAC’22 Accelerator
Prizes Special Session on Thursday, June 16, 2022.

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All delegates and exhibitors are encouraged to visit the student poster session.

IPAC’22

Main Foyer for Student Poster Session
LCOME
RECEPTION AND STUDENT POSTERS

SAPPHIRE
204-205

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9

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80

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36

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Zone

C

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84

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50

35

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Main Foyer
GRAND DIAMONDBALLROOMV3
S Zone
14

7

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W ZoneSTUDENTPOSTER

V2

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STAGE+0.80
LED 7.00*4.00

EA

IMPACT FORUM MUANGTONG THANI BANGKOK, T

17

SAPPHIRE
201
2nd floor,
registration

SAPPHIRE
202

SAPPHIRE
203

IPAC’22

Student Grants Sponsors
The accelerator community and the organizing committee of the International Particle Accelerator Conference (IPAC)
recognizes significant contribution of students. To support their development, it is crucial that they will be providing with
opportunity to interact with their peers from different countries at conference. For this reason, this conference series coordinate with numerous organizations and institutes internationally to raise funds for the student support program. The
profits from this conference series also goes towards this program.
IPAC’22 has raised THB 5,383,398 to support 71 students from 18 different countries (181 applicants from 23 countries)
to attend the conference.
The generous sponsors for student grants this year are:กรณีใช้สิ่งพิมพ์ PANTONE 354C
กรณีใช้ Web R:0 G:149 B:60

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IPAC’22

Supervised Machine Learning for Local Coupling Sources Detection in the LHC
Authors : Felix Soubelet, Tobias Hakan Bjorn Persson, Rogelio Tomas (CERN, Geneva), Elena Fol (CERN, Meyrin),Oznur Apsimon, Carsten Peter Welsch (Cockcroft Institute,
Warrington, Cheshire)

Abstract Local interaction region (IR) linear couplingin the LHC has been shown to have a negative impact
on beam size and luminosity, making its accurate
correction for Run 3 and beyond a necessity. In view ofdetermining corrections, supervised machine learning

has been applied to the detection of linear coupling sources, showing promising results in simulations. An evaluation ofdifferent applied models is given, followed by the presentation of further possible application concepts for linear coupling

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corrections using machine learning.

Conceptual Design of the FCC-ee Beam Dumping System
Authors : Alexander Michael Krainer, Marco Calviani, Anton
Lechner, Antonio Perillo-Marcone (CERN, Meyrin), Yann
Dutheil, Francois- Xavier Nuiry (CERN, Geneva), Pablo Andreu
Muñoz, Wolfgang Bartmann (CERN, Geneva 23), Rebecca
Ramjiawan (JAI, Oxford)

Abstract The Future Circular electron-positron Collider(FCC-ee) will have stored beam energies of up to 20
MJ. This is a factor 100 higher than any current or
past lepton collider. A safe and reliable disposal of thebeam onto a beam dump block is therefore critical for
operation. To ensure the survival of the dump core
blocks, transversal dilution of the beam is necessary.

To reduce the complexity of the system and guarantee high availability, an optimized, semi-passive beam dumping system
has been designed. The main dump absorber design has been optimized following recent studies for high energy dump
block materials for the LHC High Luminosity upgrade. First simulations regarding the radiation environment of the
dumping system have been carried out, allowing the definition of preliminary constraints for the integration with respect
to radiation sensitive equipment. The performance of the system has been evaluated using Monte- Carlo simulations aswell as thermomechanical Finite-Element- Analysis to investigate potential material failure and assess safety margins.
An experiment at the CERN HiRadMat facility has been carried out and preliminary results show good agreement withSUSPMF003

simulations.

Coupling Effects of Beam-Beam Interaction and Longitudinal Impedance
Authors : Chuntao Lin (University of Chinese Academy of
Sciences, Beijing), Yuan Zhang (IHEP, Beijing), Kazuhito
Ohmi (KEK, Ibaraki)

Abstract Recent studies have shown a novel coherent
head-tail instability induced by beam-beam interaction
with a large Piwinski angle. The instability has become
an important issue during the designs of CEPCand FCC-ee. Simulations have further revealed that the longitudinal impedance has a strong impact on the beamstability, squeezing the horizontal stable tune area seriously. The “cross-wake force” has been introduced to represent
beam-beam interaction. A mode coupling theory based on the localized wake (impedance) force has been developed to
explain the instability. However, the theory did not consider the effects of longitudinal impedance. In this paper, we develop
a new transverse mode coupling analysis method that could be used to study the beam- beam instability with and without
longitudinal impedance. The result shows that the distortion of longitudinal phase space trajectory and the incoherent
synchrotron tune shift induced by longitudinal impedance would reduce the stable tune area.

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IPAC’22

Investigation of Polarized Proton Spin Coherence Time at Storage Rings
Authors : Aleksei A. Melnikov, Yury Senichev (RAS/INR,Moscow),
Evgeny Syresin (JINR/VBLHEP, Dubna, Moscow region),
Alexander Aksentyev (RAS/INR, Moscow; MEPhI, Moscow)

Abstract The possibility of getting a 1000 s Spin
Coherence Time (SCT) for deuterons has been shown
experimentally at COoler SYnchrotron (COSY),
accelerator at FZJ Jülich, Germany. Reaching highvalues of SCT for protons is more challenging due toa higher anomalous magnetic moment. Obtaining sufficient proton SCT is obligatory for planned Electric Dipole Moment(EDM) search experiments at COSY and the ProtoType EDM Ring (PTR). It has been shown that the second ordermomentum compaction factor (alpha1) has to be optimized along with chromaticities to get high SCT. Three familiesof sextupoles have to be used. The optimal values of chromaticities and alpha1 are discussed. The racetrack option of

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PTR is investigated.

Controlling Landau Damping via Feed-Down From High-Order Correctors
in the LHC and HL-LHC Beam Optics
Authors : Joschua Dilly, Ewen Hamish Maclean, Rogelio
Tomas (CERN, Geneva)

Abstract Amplitude detuning measurements in the LHC
have shown that a significant amount of detuning is
generated in Beam 1 via feed-down from decapole anddodecapole field errors in the triplets of the experiment

insertion regions, while in Beam 2 this detuning is negligible. In this study, we investigate the cause of this behavior and
we attempt to find corrections that use the feed- down from the nonlinear correctors in the insertion region for amplitude

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detuning.

Studies on Top-Up Injection Into the FCC-ee Collider Ring
Authors : Patrick James Hunchak (CLS, Saskatoon, Saskatchewan), Michael Hofer (CERN, Geneva), Yann Dutheil (CERN,
Geneva 23), Rebecca Ramjiawan, Frank Zimmermann (CERN,
Meyrin), Mark James Boland (CLS, Saskatoon, Saskatchewan;
University of Saskatchewan, Saskatoon), Masamitsu Aiba
(PSI, Villigen PSI)

Abstract In order to maximize the luminosity production
time in the FCC- ee, top-up injection will be employed.
The positron and electron beams will be accelerated
to the collision energy in the booster ring before being
injected with either a small transverse or longitudinal
separation to the stored beam. Using this scheme
essentially keeps the beam current constant and,apart from a brief period during the injection process,collision data can be continuously acquired. Two suitable schemes for FCC-ee have been identified in the past and arestudied in further detail to find a suitable design for each of the four operation modes of the FCC-ee. In this paper, theintegration into the collider ring is reviewed in view of changes of collider ring layout. Tracking studies are presented andthe performance of the two schemes is compared.

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IPAC’22

Power Deposition Studies for Crystal-Based Heavy Ion Collimation in the LHC
Authors : Jean-Baptiste Potoine, Luigi Salvatore Esposito,
Anton Lechner, Andreas Waets (CERN, Meyrin), Roderik Bruce,
Rongrong Cai, Pascal Dominik Hermes, Stefano Redaelli(CERN, Geneva), Frederic Wrobel (IES, Montpellier)

Abstract The LHC heavy-ion program with 208Pb82+
beams is foreseen to benefit from a significant intensity
upgrade in 2022. A performance limitation may arise
from ion fragments scattered out of the collimators inthe betatron cleaning insertion, which risk quenchingsuperconducting magnets during periods of short beam

lifetime. In order to mitigate this risk, an alternative collimation technique, relying on bent crystals as primary collimators,
will be used in future heavy-ion runs. In this paper, we study the power deposition in superconducting magnets by meansof FLUKA shower simulations, comparing the standard collimation system against the crystal-based one. The studies focus
on the dispersion suppressor regions downstream of the betatron cleaning insertion, where the ion fragment losses are the

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highest. Based on these studies, we quantify the expected quench margin expected in future runs with 208Pb82+ beams.

Spectro-Temporal Properties of CHG Radiation
Authors : Arjun Radha Krishnan, Benedikt Büsing, Arne Held,
Hubertus Kaiser, Shaukat Khan, Carsten Mai, Zohair Usfoor,
Vivek Vijayan (DELTA, Dortmund)

Abstract The short-pulse facility at the 1.5-GeV
synchrotron light source DELTA, operated by the TU
Dortmund University, currently employs Coherent
Harmonic Generation (CHG) to produce ultrashortradiation pulses in the vacuum ultraviolet regime.

This is achieved via a laser-induced electron energy modulation and a subsequent microbunching in a dispersive section.
It is possible to manipulate the spectro-temporal properties of the CHG pulses by varying the chirp of the seed laser pulses
and the strength of the dispersive chicane. CHG spectra for different parameter sets were recorded and compared withSUSPMF009

the results of numerical simulations to reconstruct the spectra. The results of the studies will be presented.

Cooling Challenges in a NEG-Coated Vacuum Chamber of a Light
Authors : Saeid Talebi Motlagh, Amir Danaeifard, Javad Rahighi,
Farhad Saeidi (ILSF, Tehran), Farhad Zamani (University of
Kashan, Kashan)

Abstract In a light Source, unused synchrotron
radiation is being distributed along the walls of thechambers. Due to the small conductance of thechambers, vacuum pumping is based on the
distributed concept, and then non-evaporable getter(NEG) coating isextensively used. The vacuum chambers are made of copper alloys tube, and cooling circuits are weldedto the chamber to remove the heat load from the radiation generated. Filler metal is used to create a brazed joint between
the water cooling pipe and the vacuum chamber body. The thermal conductivity of the fillers is less than the vacuum
chamber body. Moreover, the water velocity in the cooling pipe must be taken into account in thermal calculations.
In this paper, we study and investigate the effects of the filler metal and the cooling water velocity in cooling the chambers.

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IPAC’22

Undulator Tapering Studies of an Echo-Enabled Harmonic Generation Based
Free-Electron Laser
Authors : Fabian Pannek, Wolfgang Carl Albert Hillert (University of Hamburg, Hamburg), Sven Ackermann, Lucas Schaper(DESY, Hamburg)

Abstract The free-electron laser (FEL) user facility
FLASH at DESY is currently undergoing an upgrade
which involves the transformation of one of its
beamlines to allow for external seeding via so-called
Echo-Enabled Harmonic Generation (EEHG).

With this seeding technique it will be possible to provide stable, longitudinal coherent and intense radiation in the XUV andsoft X-ray regime at high repetition rate. To ensure an efficient FEL amplification process, sustainable energy exchange
between the electrons and the electromagnetic field in the undulator is mandatory. Adequate adjustment of the undulator
strength along the beamline allows to compensate for electron energy loss and to preserve the resonance condition.
The impact of this undulator tapering on the temporal and spectral characteristics on the EEHG FEL radiation at 4 nm isinvestigated by means of numerical simulations performed with the FEL code GENESIS 1.3, version 4. Different tapering
methods are examined and it is shown that specific tapering of the undulator strength allows to exceed the FEL saturation

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power while maintaining a clear temporal and spectral shape of the FEL pulse.

Optical Simulation for Performance Prediction of X-Ray Optical Delay Lineat European XFEL
Authors : Marziyeh Tavakkoly (EuXFEL, Schenefeld; University of Hamburg, Hamburg), Torsten Wohlenberg (DESY,
Hamburg), Jan Grünert, Andreas Koch, Daniele La Civita,
Mikako Makita, Michael Meyer, Marc Planas, Svitozar Serkez,
Harald Sinn, Maurizio Vannoni (EuXFEL, Schenefeld)

Abstract X-ray Free Electron Lasers (XFELs) generate
short and powerful radiation pulses allowing for a wide
range of novel experiments. One of the experiments
is two-color pump-probe spectroscopy using X-rays
with controllable delay of two different wavelengths.
In this work, we discuss the method for producing

two-color pulses at the SASE3 soft X-ray beamline of the European XFEL. The technique is based on the installation of
a Magnetic Chicane (MC), which delays the electron beam, and an Optical Delay Line (ODL) that delays the x-ray beam.

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In this paper, optical aspects of the project are investigated.

Design and Simulation of the MIR-FEL Generation System at Chiang Mai
University
Abstract At the PBP-CMU Electron Linac Laboratory,
Authors : Supasin Sukara, Sakhorn Rimjaem (Chiang Mai

the system to generate MIR-FEL using the electron

University, Chiang Mai), Hideaki Ohgaki (Kyoto University,
Kyoto)

linac has been developed. In this contribution,
the design and simulation results of the MIR- FEL

generation system are presented. The system is designed as the oscillator-FEL type consisting of two mirrors and the
1.6-m permanent planar undulator. The middle of the undulator is determined as the laser beam waist. Both two mirrors
are the concave gold-coated copper mirrors placed upstream and downstream the waist at the positions of 2.956 and
2.450 m, respectively. To simulate the FEL generation, the electron beam with maximum energy of 25 MeV is performed
using the computer code GENESIS 1.3. As a result, the MIR-FEL pulses with the central wavelength range of 9.5 - 12.9µm can be obtained from the undulator strength of higher than 0.75. This requires the electron beam with macro-pulsesof at least 5 µs to saturate the FEL power with macro-pulse duration of about 1 µs. At the saturation point, the FEL
micro-pulses have the FWHM duration in picosecond scale and the total energy of 0.3 - 0.4 µJ. The construction of thepractical MIR-FEL system is conducted based on the results from this study.

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IPAC’22

Single Pass High Efficiency THz FEL
Authors : Andrew Charles Fisher, Maximilian Patrick Lenz,
Pietro Musumeci, Alexander Ody, Youna Park (UCLA, Los
Angeles), Alex Murokh (RadiaBeam, Marina del Rey, California),
Ronald Agustsson, Tara Campese (RadiaBeam, Santa Monica,
California)

Abstract Free electron lasers are an attractive option
for high average and peak power radiation in the THz
gap, a region of the electromagnetic spectrum whereradiation sources are scarce, as the required beamand undulator parameters are readily achievable withcurrent technology. However, slippage effects require

the FEL to be driven with relatively long and low current electron bunches, limiting amplification gain and output power.
We use a waveguide to match the radiation and e-beam velocities in a meter-long strongly-tapered helical undulator,
allowing energy extraction from an ultrashort 200 pC 5.5 MeV electron beam. Measurements of the e-beam spectrum
and THz FEL radiation indicated an average energy efficiency of 10%. We plan to significantly increase the efficiency by

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recirculating a portion of the radiation to seed subsequent passes as well as improve bunch compression.

Electro-Optic Sampling Based Characterization of Broad-Band High
Efficiency THz-FEL
Authors : Maximilian Patrick Lenz, Andrew Charles Fisher,
Pietro Musumeci, Alexander Ody, Youna Park (UCLA, Los
Angeles)

Abstract Extremely high beam-to-radiation energy
conversion efficiencies can be obtained in THz FEL
when using a strongly tapered helical undulator in
the zero-slippage regime where the radiation groupvelocity is matched by a circular waveguide to the electron beam longitudinal velocity in the undulator. In this paper
we report on the first electro-optic sampling based measurements of the intense broadband THz-FEL radiation pulses
generated in this regime. The THz field waveforms are reconstructed in the spatial and temporal domains by multi-shotand single-shot electro-optic sampling respectively. The field profiles are compared with the results of 3D self-consistentSUSPMF015

simulations and provide insights on the FEL dynamics in the deep non-linear regime.

Simulations of the Suitability of a DC Electron Photogun and S-Band
Accelerating Structure as Input to an X-Band Linac
Authors : Scott David Williams, Roger Paul Rassool, Suzanne
L. Sheehy, Geoffrey Taylor, Matteo Volpi (The University of
Melbourne, Melbourne, Victoria), Rebecca Auchettl, Rohan
Dowd (AS - ANSTO, Clayton)

Abstract Work has been underway for some time todesign a compact electron beamline utilising X-band
linear accelerating structures in the new Melbourne
X-band Laboratory for Accelerators and Beams(X-LAB). The original design utilised an S-band RF
photogun as an input to a pair of high gradient X-band

linear accelerating structures, but we have been motivated to investigate an alternative initial section to allow for initial
testing. This will utilise a DC photogun and S-band accelerating structure similar to those used at the Australian Synchrotron.
Simulation results incorporating space charge of a beamline composed of a DC photogun, S-band accelerating structures,and two high gradient X-band structures will be presented. These simulation results will be optimised for minimum
emittance at the end of the beamline.

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IPAC’22Development of a Detection System for Quasi-Monochromatic THz Pulse bya Spatially Modulated Electron Beam
Authors : Kota Murakoshi, Yuya Koshiba, Yuichi Tadenuma,
Peng Wang, Masakazu Washio (Waseda University, Tokyo),
Ryunosuke Kuroda (AIST, Tsukuba), Kazuyuki Sakaue (The
University of Tokyo, Bunkyo)

Abstract We have studied the generation of thebroadband THz pulse using a compact linear accelerator.
The THz pulse is generated by control of an electron
beam angle to Cherenkov radiation angle. In addition, we
have succeeded in producing a quasi- monochromatic
THz pulse by the spatially modulated electron beam bypassing through a slit. This work aims to develop a detection system to elucidate the spectrum of the quasi- monochromatic
THz pulse. To detect it stably in a noisy radiation environment, the stability of probe laser system for Electro Optic
sampling and timing synchronization system are important. In this conference, the generation method of each THz pulses,

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the results of development of detection system, and future prospect will be reported.

Visualisation of Pareto Optimal Spaces and Optimisation Solution Selection
Using Parallel Coordinate Plots
Authors : Samuel Smith, Robert Apsimon, Graeme Burt,
Matthew Southerby (Cockcroft Institute, Lancaster), Sadiq
Setiniyaz (Cockcroft Institute, Warrington, Cheshire; Lancaster
University, Lancaster)

Abstract In this paper, we build on previous workwhere multi-objective genetic algorithms were used to
optimise RF cavities using non- uniform rational basis
splines (NURBS) to improve the cavity geometries andreduce peak fields. These optimisations can produce
thousands of Pareto optimal solutions, from which a final

cavity solution must be selected based on design criteria, such as accelerating gradient and power requirements. As all
points are considered equally optimal, this can prove difficult without further analysis. Here we focus on the visualisationof the Pareto optimal points and the final solution selection process. We have found that the use of clustering algorithms
and parallel coordinate plots (PCPs) provide the best way to represent the data and perform the necessary trade-offs

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between the peak fields and shunt impedance required to pick a final design.

Investigation of Polarization Dependent Thomson Scattering in an EnergyRecovering Linear Accelerator on the Example of Mesa
Authors : Christoph Lukas Lorey, Atoosa Meseck (KPH, Mainz)

Abstract At the Johannes Gutenberg University(JGU) in Mainz, a new accelerator is currently underconstruction in order to deliver electron beams of up

to 155 MeV to two experiments. The Mainz Energy-recovering Superconducting Accelerator (MESA) will offer two modesof operation, one of which is an energy-recovering (ER) mode. As an ERL, MESA, with it’s high brightness electron beam,
is a promising accelerator for supplying a Thomson back scattering based Gamma source. Furthermore, at MESA, thepolarization of the electron beam can be set by the injector. The aim of this work is to provide a concept and comprehensive
analysis of the merit and practical feasibility of a Thomson backscattering source at MESA under consideration of beampolarization and transversal effects. In this paper, an overview and results of our semi analytical approach to calculate
various Thomson back scattering light source scenarios at MESA will be given. Furthermore we will discuss the benefitsof using polarized electrons in combination with a polarized laser beam.

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IPAC’22

Generation of Coherent THz Transition Radiation for Time Domain Spectroscopy
at the PBP-CMU Electron Linac Laboratory
Authors : Siriwan Pakluea (Chiang Mai University, ChiangMai), Sakhorn Rimjaem, Jatuporn Saisut, Chitrlada Thongbai(Chiang Mai University, Chiang Mai; ThEP Center, Bangkok),
Monchai Jitvisate (Suranaree University of Technology,
Nakhon Ratchasima)

Abstract The accelerator system at the PBP-CMU
Electron Linac Laboratory is used to generate terahertz
transition radiation (THz-TR). Due to broad spectrum,
it can be used as the light source for THz time-domain
spectroscopy (TDS) to measure both the intensity andphase of the THz signal. This contribution presents

the generation of the THz-TR produced from 10-20 MeV electron beams and the system preparation for THz TDS. The
electron bunches, which are compressed to have a length of femtosecond scale at the experimental station, is used togenerate the THz-TR using a 45°-tilted aluminum foil as a radiator. The radiation properties including angular distribution,
polarization and radiation spectrum are measured in the accelerator hall and at the TDS station. The radiation spectral
range covers up to 2.3 THz with the peak power of 0.5 - 1.25 MW is expected. The effects of electron bunch distribution,
divergence of the beam and influence of optical components on the radiation properties were studied. The results showthat the considered effects have a significant impact on the TR properties. The Information will be used in the TR

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characterization that is needed to be interpreted carefully.

Field Enhanced, Compact S-Band Gun Employing a Pin Cathode
Authors : Reza Bazrafshan, Timm Rohwer (Deutsches
Elektronen Synchrotron (DESY) and Center for Free Electron
Science (CFEL), Hamburg), Nicholas Hill Matlis (CFEL,
Hamburg), Moein Fakhari, Klaus Floettmann, Franz Kaernter(DESY, Hamburg)

Abstract S-band RF-guns are highly developed for
production of low emittance relativistic electron bunches,but need powerful klystrons for driving. Here, we
present the design and first experimental tests of acompact compact S-band gun, which can accelerate
electrons up to 180 keV powered by only 10 kW froma compact rack-mountable solid-state amplifier.

A pin-cathode is used to enhance the RF electric field on the cathode up to 100 MV/m as in large-scale S-band guns.
An electron bunch is generated through photoemission off a flat copper surface on the pin excited by a UV laser pulse
followed by a focusing solenoid producing a low emittance bunch with 0.1 mm mrad transverse emittance for up to 100
fC bunch charge. We are currently in the conditioning phase of the gun and first experiments show good agreement withsimulations. The compact gun will serve three purposes: (i) it can be used directly for ultrafast electron diffraction; (ii) as an
injector into a THz booster producing 0.3MeV to 2 MeV electron bunches for ultrafast electron diffraction; (iii) The systemin (ii) serves as an injector into a THz linear accelerator producing a 20 MeV beam for the AXSIS X-ray source project.

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IPAC’22

CrYogenic Brightness-Optimized Radiofrequency Gun (CYBORG)
Authors : Gerard Emile Lawler, Atsushi Fukasawa, Nathan
Majernik, Jake Riley Parsons, James Rosenzweig, Yusuke
Sakai, Arathi Suraj (UCLA, Los Angeles, California)

Abstract Producing higher brightness beams at thecathode is one of the main focuses for future
electron beam applications. For photocathodes
operating close to their emission threshold, the cathodelattice temperature begins to dominate the minimum

achievable intrinsic emittance. At UCLA, we are designing a radiofrequency (RF) test bed for measuring the temperaturedependence of the mean transverse energy (MTE) and quantum efficiency for a number of candidate cathode materials.
We intend to quantify the attainable brightness improvements at the cathode from cryogenic operation and establish a
proof-of-principle cryogenic RF gun for future studies of a 1.6-cell cryogenic photoinjector for the UCLA ultra compact XFEL
concept (UC-XFEL). The test bed will use a C-band 0.5-cell RF gun designed to operate down to 45 K, producing an on-axis
accelerating field of 120 MV/m. The cryogenic system uses conduction cooling and a load-lock system is being designed

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for transport and storage of air-sensitive high brightness cathodes.

Performance Report of the SOLEIL Multipole Injection Kicker
Authors : Randy Ollier, Patrick Alexandre, Rachid Ben El Fekih,Alexis Gamelin, Nicolas Hubert, Marie Labat, Amor Nadji,
Laurent Stanislas Nadolski, Marie-Agnès Tordeux (SOLEIL,
Gif-sur-Yvette)

Abstract A Multipole Injection Kicker (MIK) was
installed in a short straight section of the SOLEIL
storage ring and successfully commissioned in 2021.
A small horizontal orbit distortion in the micrometer range
was achieved outperforming the standard bump-based
injection scheme installed in a 12-m long straight section.

Refined studies have been conducted to fully understand and further improve the performance of the device. Indeed, anovel generation of the MIK will be the key element for the injection scheme of the SOLEIL Upgrade. We report simulation
studies and the latest MIK experimental performance. Both injected and stored beam-based measurements were performed
using new types of diagnostics with turn-by-turn capability (Libera Brillance+ BPM, KALYPSO: 2x1D imaging). The residual
perturbations on the beam positions and sizes were measured; the magnetic field of the MIK device was reconstructed. An
unexpected kick was detected in the vertical plane and an active correction implemented to cancel the resulting perturbation.

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IPAC’22

Goubau-Line Set Up for Bench Testing Impedance of IVU32 Components
Authors : Paul Ignatius Volz (HZB, Berlin), Atoosa Meseck(HZB, Berlin; KPH, Mainz)

Abstract The worldwide first in-vacuum ellipticalundulator, IVUE32, is being developed at HelmholtzZentrum Berlin. The 2.5 m long device with a period
length of 3.2 cm and a minimum gap of about 7 mm

is to be installed in the BESSY II storage ring. It will deliver radiation in the soft X-ray range to several beamlines. The
proximity of the undulator structure to the electron beam makes the device susceptible to wakefield effects which can
influence beam stability. A complete understanding of its impedance characteristics is required prior to installation andoperation, as unforeseen heating of components could have catastrophic consequences. To understand and measure the
IVU's impedance characteristics a Goubau-Line test stand is being designed. A Goubau-line is a single wire transmission
line for high frequency surface waves with a transverse electric field resembling that of a charged particle beam out toa certain radial distance. A concept optimized for bench testing IVUE32-components will be discussed, microwave

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simulations will be presented together with first measurements from a test stand prototype.

Status and Powering Test Results of HTS Undulator Coils at 77 K for Compact
FEL Designs
Authors : Sebastian C. Richter (CERN, Geneva; KIT, Karlsruhe),Amalia Ballarino, Thomas Henricus Nes, Daniel Schoerling(CERN, Geneva), Axel Bernhard, Anke-Susanne Mueller (KIT,
Karlsruhe)

Abstract The production of low emittance positron
beams for future linear and circular lepton colliders,like CLIC or FCC-ee, requires high-field damping
wigglers. Just as compact free-electron lasers (FELs)
require high-field but as well short-period undulators
to emit high energetic, coherent photons.

Using high-temperature superconductors (HTS) in the form of coated ReBCO tape superconductors allows higher
magnetic field amplitudes at 4 K and larger operating margins as compared to low-temperature superconductors,
like Nb-Ti. This contribution discusses the development work on superconducting vertical racetrack (VR) undulator
coils, wound from coated ReBCO tape superconductors. The presented VR coils were modularly designed witha period length of 13 mm. Powering tests in liquid nitrogen of multiple vertical racetrack coils were performed at
CERN. The results from the measurements are presented for three VR coils and compared with electromagnetic
simulations.

SUSPMF025

IPAC’22

Hall Probe Magnetic Measurement of 50 mm Period PPM Undulator
Authors : Saif Mohd Khan, Ganeswar Mishra (Devi Ahilya
University, Indore), Mona Gehlot (MAX IV Laboratory, Lund),Hussain Jeevakhan (NITTTR, Bhopal)

Abstract In this paper, we present the latest
upgradation of Hall Probe magnetic measurement
system. The Hall Probe measurement system is
upgraded with position measuring detectors and 3D
F.W. Bell Teslameter. The field integrals and the phaseerrors are calculated with a new user friendly MATLAB code. The integrated multipoles both normal and skew components
are measured and discussed in the paper. The proposed activities on 300 mm length prototype asymmetric undulator and
50 mm quasi period, six period length at Laser Instrumentation and Insertion Device Application laboratory of Devi Ahilya

SUSPMF026

Vishwa Vidyalaya (DAVV), Indore, India has been discussed and design components are presented.

Single-Sided Pumped Compact Terahertz Driven Booster Accelerator
Authors : Tobias Kroh, Reza Bazrafshan, Nicholas Hill Matlis(Deutsches Elektronen Synchrotron (DESY) and Center for
Free Electron Science (CFEL), Hamburg), Moein Fakhari,
Mikhail Pergament, Timm Rohwer, Mostafa Vahdani, Dongfang
Zhang (CFEL, Hamburg), Franz Xaver Kaertner (Deutsches
Elektronen Synchrotron (DESY) and Center for Free Electron
Science (CFEL), Hamburg; The Hamburg Center for Ultrafast
Imaging, University of Hamburg, Hamburg), Keigo Kawase(JAEA, Kizugawa)

Abstract Scaling the RF-accelerator concept toterahertz (THz) frequencies brings several compelling
advantages, including compactness, intrinsic timing
between the photoemission and driving field sources,and high field gradients associated with the short THz
wavelength and high breakdown threshold. Recent
demonstrations of such THz powered accelerators
relied on two counter-propagating single-cycle THz
pulses. However, to achieve high energy gains in
the acceleration process high energy THz pulses areneeded which in turn require complex optical setups. Here, we present on the development of a matchbox sized multi-layered
accelerator designed to boost the 50 keV output of a DC electron gun to energies of ~400 keV that only requires a single
THz pulse to be powered. An integrated tunable mirror inside the structure interferes the front of the driving THz pulse with
its rear part such that the field in the interaction region is optimized for efficient acceleration. This reduces the complexityof the required optical setup. Such a compact booster accelerator is very promising as electron source in ultrafast electron
diffraction experiments and as booster stage prior to THz based LINACs.

SUSPMF027

IPAC’22

From Lossy THz Accelerating Waveguides to the Constant Gradient
Design of a Dielectric Loaded Waveguide
Authors : Max Joseph Kellermeier, Thomas Vinatier (DESY,
Hamburg), Ralph Wolfgang Assmann (DESY, Hamburg;
LNF-INFN, Frascati), Wolfgang Carl Albert Hillert (Universityof Hamburg, Hamburg)

Abstract In recent years emerging high power THz
sources advanced the high gradient acceleration ofultra-short bunches, towards new high brightness
beams. So far, dissipation of power in the lossy
accelerating structure is often considered as negligible
which leads to the assumption of a constant accelerat

ing field along the beam axis. In our treatment, finite conductivity of copper and dielectric loss is included in beam dynamics
simulations of acceleration in a circular dielectric loaded waveguide. Apart from the reduced final energy especially thelongitudinal focal point is affected by the modified field profile. Two approaches to overcome the effects are presented.
The first one simply assumes a more powerful THz source to compensate the loss. In contrast, the second approach aims
for recovering the ideal case by longitudinally tapering the cross section to achieve a constant gradient design. Regardlessof the approach undertaken in future experiments, the power dissipation significantly increases the requirements of the

SUSPMF028

driving THz source in terms of peak power or pulse length.

Optimized Dielectric Loaded Waveguide Terahertz LINACs
Authors : Mostafa Vahdani (CFEL, Hamburg; University of
Hamburg, Hamburg), Moein Fakhari (DESY, Hamburg), Franz
Xaver Kaertner (Deutsches Elektronen Synchrotron (DESY)
and Center for Free Electron Science (CFEL), Hamburg;
The Hamburg Center for Ultrafast Imaging, University of
Hamburg, Hamburg)

Abstract Dielectric loaded waveguides (DLW) poweredby multicycle terahertz (THz) pulses have shownpromising performance as compact linear accelerators
due to higher breakdown fields at THz frequencies
compared to conventional RF components. By changing
the dielectric dimensions one can control phase andgroup velocities of the THz pulse inside the DLW.

Since optimum waveguide dimensions are dependent on initial electron energy, THz pulse energy, and etc., it is worthwhile
to determine optimum values for different conditions to maximize final kinetic energy. In this work, we present a combined
analytical/numerical guide to determine the optimum DLW parameters for single on- axis electron acceleration. We also
introduce normalized graphic representations to visualize optimum designs for different initial electron and THz pulse

SUSPMF029

energies.

Diagnosis of Transverse Emittance in Laser-Driven Ion Beam
Authors : Tatsuhiko Miyatake, Ibuki Takemoto, Yukinobu
Watanabe (Kyushu University, Kasuga-Shi), Thanh-Hung Dinh,
Kondo Kiminori, Kotaro Kondo, Kando Masaki, Masaharu
Nishikino, Mamiko Nishiuchi, Kojima Sadaoki, Hironao Sakaki(National Institutes for Quantum and Radiological Scienceand Technology, Kyoto)

Abstract Research on laser-driven acceleration
mechanisms is important to develop a next-generationcompact accelerator. Especially, understandingtransverse emittance is extremely important indetermining the characteristics of the accelerated beamwith a laser-driven acceleration mechanism. Somepapers show the emittance of laser-driven protons sofar, but parameters that contribute to an emittance have not been systematically diagnostics, so the emittance controlling
methods have not been understood. Therefore, we plan to control the transverse emittance for establishing an ion
accelerator with laser-driven acceleration mechanisms. We report on the diagnostics result of the correlation between thetransverse emittance of laser-driven protons and various parameters of the laser or target.

SUSPMF030

IPAC’22

Beam Dynamics and Drive Beam Losses Within a Planar Dielectric Wakefield
Accelerator
Authors : Toby Joseph Overton (Cockcroft Institute,
Warrington, Cheshire), Yuri Saveliev (Cockcroft Institute,
Warrington, Cheshire; STFC/DL/ASTeC, Daresbury,
Warrington, Cheshire), Thomas Hywel Pacey(STFC/DL/ASTeC, Daresbury, Warrington, Cheshire), Guoxing
Xia (UMAN, Manchester)

Abstract Beam-driven dielectric wakefield accelerators(DWA) have the potential to provide accelerating
gradients in the GV/m range. The transverse dynamics
in such devices need to be understood to avoid
instabilities over long transport distances and facilitate
beam matching to specific applications (e.g. FELs).
This presentation details simulation studies of themagnitude of beam-breakup instability (BBU) in planar dielectric lined waveguides (DLWs). These are for DWA drive beams,
with high charge and momentum that can be produced at current facilities. Using a series of perpendicular DLW segments
has been proposed to control instabilities over larger distances. Using self- developed software, the beam dynamics of adrive beam within a DLW are simulated and the magnitude of beam losses along a DLW of varying lengths calculated andbeam quality preservation investigated. Methods to reduce transverse instabilities have been explored, and the impactof these on the length of a possible DWA acceleration stage are investigated. An acceleration stage with m-scale length,

SUSPMF031

consisting of multiple alternating planar DLWs, is suggested and preservation of beam quality along this distance is shown.

Temporal and Spatial Characterization of Ultrafast Terahertz Near- Fields for
Particle Acceleration
Authors : Annika Gabriel, Matthias Clemens Hoffmann, Emilio
Alessandro Nanni, Mohamed Othman (SLAC, Menlo
Park,California)

Abstract We have measured the THz near-field inorder to inform the design of improved THz-frequency
accelerating structures. THz- frequency accelerating
structures could provide the accelerating gradientsneeded for next generation particle accelerators with compact, GV/m-scale devices. One of the most promising THz
generation techniques for accelerator applications is optical rectification in lithium niobate using the tilted pulse front method.
However, accelerator applications are limited by significant losses during transport of THz radiation from the generating
nonlinear crystal to the acceleration structure. In addition, the spectral properties of high-field THz sources make it
difficult to couple THz radiation into accelerating structures. A better understanding of the THz near-field source properties
is necessary for the optimization of THz transport and coupling. We have developed a technique for detailed
measurement of the THz near-fields and used it to reconstruct the full temporal 3D THz near-field close to the LN emission
face. Analysis of the results from this measurement will inform designs of novel structures for use in THz particle acceleration.

SUSPMF032

IPAC’22

Progress in Multi-MeV Energy Gain in a Relativistic Dielectric Laser Accelerator
Authors : Sophie Crisp, Alexander Ody (UCLA, Los Angeles),Pietro Musumeci (UCLA, Los Angeles, California)

Abstract We present progress and an experimental
plan for multi-MeV relativistic energy gain in a dielectriclaser-driven accelerator (DLA). Using a 780 nm, 100
fs pulse-front-tilted laser, we achieve interaction with

6 MeV electrons over a 4 mm long structure with 800 nm period. To compensate for resonant defocusing effects, the laser
pulse is imprinted with a phase mask, applied by a Spatial Light Modulator, which uses alternating phase focusing (APF)
to achieve stable beam transport. The DLA is mechanically mounted with a variable sized gap (600-1200 nm) in order tomaximize transmission while maintaining high gradient within the channel. The combination of high interaction length and

SUSPMF033

use of APF confines and accelerates the electrons by up to 3.5 MeV.

Theoretical Study of Laser Energy Absorption Towards Novel Bright Proton
and Electron Sources
Authors : Iuliana Mariana Vladisavlevici, Emmanuel d’Humières(CELIA, Talence), Daniel Vizman (West University of Timisoara,
Timisoara)

Abstract Our main goal is to describe and model
the energy transfer from laser to particles, from thetransparent to less transparent regime of laser-plasmainteraction in the ultra-high intensity regime, and using
the results obtained to optimize laser ion acceleration.

We propose a theoretical model of energy transfer, assuming that most of the laser energy will be transferred to hot electrons.
The model is further tested and corrected through 2D particle-in-cell simulations performed with SMILEI*. Varying the target
density and thickness, we studied the optimal parameters for the maximum conversion efficiency of the laser energy toparticles. We investigate a model for a near-critical density plasma between 0.5-20 nc (where nc = 1.1·10^21 cm^-3 is thecritical density) driven by a laser pulse of intensity in the range 10^18-10^23 W/cm^2 and the pulse duration in the range
10- 100 fs. Theoretical modelling of the predominant laser-plasma interaction mechanisms predicts the particle energy
and conversion efficiency optimization **,***. Our studies led to an optimization of the target areal density for maximizing
proton acceleration for a laser intensity of 10^22 W/cm^2.

SUSPMF034

IPAC’22Developing Beam Options for Future Fixed Target Experiments in the CERN
North Area Within the Framework of of the Conventional Beams Working
Group of Physics Beyond Colliders
Authors : Carlo Alberto Mussolini (CERN, Geneva; JAI, Oxford),
Dipanwita Banerjee, Johannes Bernhard, Nikolaos Charitonidis,
Gian Luigi D’Alessandro, Alexander Gerbershagen, Bastien
Rae, Silvia Schuh-Erhard (CERN, Geneva), Elisabetta Giulia
Parozzi (CERN, Geneva; INFN MIB, MILANO; Universita Milano
Bicocca, MILANO), Markus Brugger (CERN, Meyrin)

Abstract The Physics Beyond Colliders initiative at
CERN aims to exploit the full scientific potential of the
CERN accelerator complex and its scientific infrastructure
for particle physics studies complementary to current
and future collider experiments. Several experiments
have been proposed to fully utilize and further
advance the beam options for the existing fixed target
experiments present in the North Experimental

Area of the CERN SPS. We report here on progress with an RF-separated beam option for the AMBER experiment, following
a recent workshop on this topic. In addition we will cover the status of studies for ion beams for the NA60+ experiment aswell as those for high intensity beams for kaon physics and Feebly Interacting Particles searches. With the first beams
available in 2021 after a long shutdown, several muon beam options could also be tested for the NA64mu, MUonE andSUSPMF035

AMBER experiments.

Magnetic Characterization of a Superconducting Transverse Gradient
Undulator for Compact Laser Wakefield Accelerat-Driven FEL
Authors : Kantaphon Damminsek, Axel Bernhard, Anke-Susanne
Mueller, Maisui Ning, Yimin Tong (KIT, Karlsruhe), Sebastian C.
Richter (CERN, Geneva), Robert Rossmanith (DESY, Hamburg),
Andreas Wolfgang Grau (KIT, Eggenstein-Leopoldshafen)

Abstract Combining a superconducting transverse
gradient undulator (TGU) with a Laser Wakefield
Accelerator (LWFA) is a potential key for realizing avery compact Free Electron Laser (FEL). A 40- periodsuperconducting TGU has been fabricated andcharacterized at Karlsruhe Institute of Technology (KIT).

The superconducting TGU has been commissioned off-line, step by step reaching its final operational parameters.
A specially designed set-up for mapping the magnetic field in the TGU’s extremely narrow gap has been installed,commissioned and employed for the magnetic characterization. In this contribution, we report on the operational
experience of the TGU and on the magnetic characterization measurement. This work is supported by the BMBF
project 05K19VKA PlasmaFEL (Federal Ministry of Education and Research) and the Development and Promotion of
Science and Technology Talents Project (DPST).

SUSPMF036

IPAC’22

The Propagation of Laser Accelerated Pulsed Beams in Underdense Plasma
Authors : Hao Cheng, Dongyu Li, Yuze Li, Chen Lin, Xueqing
Yan, Yang Yan, Tong Yang (PKU, Beijing)

Abstract Laser ion acceleration has become a promising
new compact accelerator due to its ultra-high field
gradient and exceptional beam properties including
low emittance, high intensity and short pulse duration*.

To apply ion beam, it is previously focused by focusing elements, such as magnet quadrupoles**, solenoids***, andlaser-triggered micro-lenses****. Plasma has also been considered as a capable medium for beam transport, which
effectively neutralize the beam to relax space charge restriction and sustain large electromagnetic fields. We have
performed 2D-PIC simulations to investigate interaction of pulsed proton beam with underdense plasma, focusing
on the evolution of beam quality. An injection of pulsed proton beam into underdense plasma generates wakefields andspontaneous magnetic fields, which simultaneously effect the proton quality. The wakefields and the spontaneous magnetic
fields continuously deflect the beam, resulting in much less increment of beam divergence in plasma than in vacuum.
It indicates the feasibility and effectiveness of plasma as beam transport element for proton beam, greatly promoting the

SUSPMF037

utilization of laser accelerated pulsed proton beam.

Beam Matching in an Elliptical Plasma Blowout Driven by Highly Asymmetric
Flat Beams
Authors : Pratik Manwani, Havyn Skyler Ancelin, Nathan
Majernik, James Rosenzweig (UCLA, Los Angeles, California),
Monika Yadav (Cockcroft Inst itute, Warrington, Cheshire;
The University of Liverpool, Liverpool; UCLA, Los Angeles,
California), Gerard Andonian (RadiaBeam, Marina del Rey,
California; UCLA, Los Angeles, California)

Abstract Beams having highly asymmetric emittanceare foreseen at AWA and FACET facilities. The
high aspect ratio produces a blowout region that is
elliptical in cross section and this asymmetry in theion column structure creates an asymmetry in thefocusing in the two transverse planes. The ellipticityof the plasma blowout decreases with increase in thenormalized peak current and gradually approaches anaxisymmetric structure. A matching condition for the beam envelope inside the elliptical blowout is introduced. Simulations
are performed to calculate the ellipticity of the resultant elliptical wakefield based on the initial beam parameters and arematched with analytical calculations. This work also explores the parameter space that would be achievable in the AWA
and FACET facilities, and plasma profiles required to match these beams are discussed.

SUSPMF038

IPAC’22

An Energy Dechirper for Laser-Accelerated Proton Based on Standing Wave
Wakefield Superposition
Authors : Tong Yang, Hao Cheng, Yanlv Fang, Zhen Guo,
Dongyu Li, Chen Lin, Minjian Wu, Yadong Xia, Xueqing Yan,
Yang Yan (PKU, Beijing)

Abstract Proton beams originating from laser-plasma
accelerators have broad energy spread*, whichmakes it difficult to preserve their high quality duringtransport to applications.Particularly, the pulse duration
will increase. To improve on this, the study realizeda scheme that applies an energy dechirper based on laser-driven wakefield. When axially side-by-side ultra-intensive
laser pulses are injected into a plasma channel from the side of the channel, the axial wakefield in the plasma is in form ofstanding wave approximately. Two standing waves with a fixed spatial and temporal phase difference of pi/4 superimpose
into a traveling wave form. The key of the scheme is that the traveling wave phase velocity can match with the velocity ofmulti-MeV proton beam. And under the velocity match condition, the proton beam incident axially into the plasma channel
is set a positive energy chirp by the traveling wave wakefield. The paper presents initial simulation work to model thisdechirper scheme. The energy dechirper offers the possibility of producing high power,quasimonoenergetic and

SUSPMF039

sub-nanosecond proton pulses for ultra-fast science,ion fusion,quality transport and cascade acceleration.

Performance Characterisation of Ultra-Thin MgO Film on Metal Photocathodes
Authors : Christopher Benjamin (STFC/DL/ASTeC, Daresbury,
Warrington,Cheshire; University of Warwick, Coventry),
Lee Jones, TimNoakes (Cockcroft Institute, Warrington,
Cheshire;STFC/DL/ASTeC, Daresbury, Warrington, Cheshire),
LiamAnthony James Soomary (Cockcroft Institute,
Warrington,Cheshire; STFC/DL/ASTeC, Daresbury,
Warrington, Cheshire; TheUniversity of Liverpool, Liverpool),
Hugh Michael Churn(STFC/DL/ASTeC, Daresbury, Warrington,
Cheshire), Gavin Bell(University of Warwick, Coventry)

Abstract The performance expected from the next
generation of electron accelerators is driving research
into photocathode technology as this fundamentally
limits the achievable beam quality. The performance
characteristics of a photocathode are most notably;
normalised emittance, brightness and energy spread*.
These factors can be defined by surface propertiesof the cathode, including the work function (WF), theintrinsic emittance and the quantum efficiency (QE)of the photocathode. Ultra-thin Oxide films on metal
substrates have been shown to lower the WF of thesurface, enhancing commonly utilised metal photocathodes, potentially improving lifetime and performance characteristics**. The surface properties of ultra-thin MgO films grown on polycrystalline Cu and Ag photocathodes are investigatedusing; Scanning Tunnelling Microscopy (STM), X-Ray Photoelectron Spectroscopy (XPS) and QE measurements. Additionally, we measure the Transverse Energy Distribution Curves (TEDC) for these photocathodes under illumination at
various wavelengths using ASTeC’s Transverse Energy Spread Spectrometer (TESS)*** and extract the Mean Transverse
Energy (MTE).

SUSPMF040

IPAC’22

Commissioning of a High-Gradient X-band RF Gun Powered by Short RF Froma Wakefield Accelerator
Authors : Wei Hou Tan (Northern Illinois University, DeKalb,
Illinois), Darrell Scott Doran, Gwanghui Ha, Wanming Liu, John
Gorham Power, Charles Whiteford, Eric Edson Wisniewski(ANL, Lemont, Illinois), Chunguang Jing (ANL, Lemont, Illinois;
Euclid TechLabs, Solon, Ohio), Xueying Lu, Philippe
Regis-Guy Piot (ANL, Lemont, Illinois; Northern Illinois University,
DeKalb, Illinois), Sergey P. Antipov, Ernest William Knight,
Sergey Vladimirovich Kuzikov (Euclid TechLabs, Solon, Ohio)

Abstract An important aspect toward producing brightelectron beams consists in rapidly accelerating thebeam to mitigate detrimental effects from space-charge
effects. A high-gradient X-band (11.7- GHz)
photoinjector developed by Euclid Techlabs, wasrecently commissioned at the Argonne Wakefield
Accelerator (AWA). The system comprises a 1+1/2-cell
RF gun powered by short RF pulses generated as a
train of high-charge bunches from the AWA accelerator
passes through a slow-wave power extraction andtransfer structure. The RF photoinjector was reliably operated with electric fields in excess of 300 MV/m on thephotocathode surface free of breakdown and with an insignificant dark-current level. We report on the RF-gun setup,
commissioning, and the associated beam generation via photoemission. The experimental results are compared withSUSPMF041

numerical simulations when applicable.

Laser-Driven Plasma Nuclear Fusion Based on Nanowire Array Structure
Using Kilojoule-ns-Scale Laser
Authors : Defeng Kong, Zhengxuan Cao, Wenjun Ma, Zhusong
Mei, Zhuo Pan, Pengjie Wang, Shirui Xu, Xueqing Yan (PKU,
Beijing)

Abstract Laser-driven nuclear physics has aroused
extensive concerning. However, the obstacle ofvolumetric deposition for laser energy restricts the plasma
temperatures for the nuclear reaction. Novel target

structures are explored as a method to strengthen laser- plasma coupling and improve the production rate. Here we
employ the ordered high aspect ratio deuterated polyethylene nanowire arrays which can extend penetration depth oflaser into materials and increase laser absorption significantly. High energy density plasma for fusion has been provided
by the radiation of the nanostructure with 1.8 kJ, 1 ns laser pulses focused to 10^15 W/cm^2. Plasma diagnosis indicate
one order of magnitude enhancement of electron emissions and triple improvement of bremsstrahlung radiation emissions
from the nanowire arrays compared to the flat targets, which shows the electric return currents and plasma collision heat
the nanowires and cause wires to explode. It results in the generation of numerous neutrons from DD nuclear fusion
with the yield of 10^6 per shot.

SUSPMF042

IPAC’22

Performance of Automated Synchrotron Lattice Optimisation Using Genetic
Algorithm
Authors : Xuanhao Zhang, Suzanne L. Sheehy (The Universityof Melbourne, Melbourne, Victoria)

Abstract Rapid advances in superconducting magnet
and related accelerator technology opens many
unexplored possibilities for future synchrotron designs.
We present an efficient method to probe the feasible

parameter space of synchrotron lattice configurations. Using this method, we can converge on a suite of optimal solutions withmultiple optimisation objectives. It is a general method that can be adapted to other lattice design problems with different
constraints or optimisation objectives. In this method, we tackle the lattice design problem using a multi- objective genetic
algorithm. The problem is encoded by representing the components of each lattice as columns of a matrix. A large populationof semi-randomly generated lattices are evolved over many generations using cross-over and random mutation operators.
The lattices are ranked based on a fitness function that accounts for constraint violation and objective satisfaction. This new
method is an improvement over the neural network based approach* in terms of computational resources. We evaluate the

SUSPMF043

performance and limitations of this new method and discuss the potential to utilise this method in other lattice design applications.

The Zgoubidoo Python Framework for Ray-Tracing Simulations With Zgoubi:
Applications to Fixed-Field Accelerators
Abstract The study of beam dynamics in accelerators
Authors : Marion Vanwelde, Eustache Gnacadja, Nicolas Pauly,

featuring main magnets with complex geometries such

Eliott Ramoisiaux, Robin Tesse (ULB, Bruxelles),as Fixed Field Accelerators (FFAs) requires simulation

Cédric Hernalsteens (CERN, Meyrin; ULB, Bruxelles)

codes allowing step-by- step particle tracking in complex
magnetic fields, such as the Zgoubi ray-tracing code.

To facilitate the use of Zgoubi and to allow readily processing the resulting tracking data, we developed a modern
Python 3 interface, Zgoubidoo, using Zgoubi in the backend. In this work, the key features of Zgoubidoo are illustrated bydetailing the main steps to obtain a non-scaling FFA accelerator from a scaling design. The results obtained are in excellent
agreement with prior results, including the tune computation and orbit shifts. These results are enhanced by Zgoubidoo
beam dynamics analysis and visualization tools, including the placement of lattice elements in a global coordinate systemand the computation of linear step-by-step optics. The validation of Zgoubidoo on conventional scaling and non-scaling

SUSPMF044

FFA designs paves the way for future uses in innovative FFA design studies.

Authors : Adam F. Steinberg, Robert Appleby (UMAN, Manchester),
Suzanne L. Sheehy (The University of Melbourne, Melbourne,
Victoria)

Abstract Fixed Field Alternating Gradient Accelerators
have been proposed for a wide range of challenges,
including rapid acceleration in a muon collider, andlarge energy acceptance beam transport for medical
applications. A disadvantage of these proposals is thehighly nonlinear field profile required to keep the tune energy- independent, known as the scaling condition. It has beenshown computationally that approximately constant tunes can be achieved by addition of nonlinear fields that do not follow
this scaling law, however the impacts of these nonlinearities are not well understood. Here, we apply the methods of Lie
Algebra to nonlinearities in fixed field accelerators, to better characterise their impact on the tune and dynamic aperture.
These results are verified by simulation using Zgoubi. As a model use case, we investigate the degree of tunecompensation that can be achieved in a fixed field accelerator for ion cancer therapy.

SUSPMF045

IPAC’22

Exploring Accelerators for Intense Beams With the IBEX Paul Trap
Authors : Jake Flowerdew (University of Oxford, Oxford),
David John Kelliher, Shinji Machida, Suzanne L. Sheehy(STFC/RAL/ASTeC, Chilton, Didcot, Oxon)

Abstract The intensity frontier has called for new
initiatives in hadron accelerator design in order toaccommodate space charge dominated beams.
Octupoles are often used to dampen beam instabilities
caused by space charge, however the insertion ofoctupole magnets leads to a nonintegrable lattice which reduces the area of stable particle motion. One proposed solution
is Quasi-Integrable optics (QIO), where the octupoles are inserted between a specially designed lattice called a T-insert.
An octupole with a strength that scales as 1/ß3 is applied in the nonlinear region to create a time independent octupole
field, leading to a lattice which is close to integrable and robust to small perturbations. IBEX is a Paul trap which allows
the transverse dynamics of a collection of trapped particles to be studied, mimicking the propagation through multiple
quadrupole lattice periods, whilst remaining stationary in the laboratory frame. In order to test QIO at the IBEX experiment,
it has recently undergone an upgrade to allow for the creation of octupole fields. We present our recent commissioning

SUSPMF046

results of the IBEX experiment along with our simulation results of our proposed experiment to test QIO.

Studies of ECR Plasmas and Material Modifications/synthesis Using Low
Energy Ion Beam Facility at IUAC
Authors : Puneeta Tripathi, Pravin Kumar, Shushant Kumar
Singh (IUAC, New Delhi)

Abstract The ECR ion sources are widely used to
produce high intensities of highly charged positiveions*. To increase their performance further, several
techniques are employed. The addition of lighter gas

into the main plasma (so-called gas mixing) shows a substantial effect on the charge state distribution of highly charged
ions. Although many theoretical models were used to explain this gas mixing effect, yet it is not fully understood. The
low energy ion beam facility (LEIBF) at Inter-University Accelerator Centre (IUAC), New Delhi, India, which comprises
a 10 GHz all-permanent magnet NANOGAN ECR source placed on a high voltage platform (400kV) has been used todevelop several plasmas for the physical understanding of ions production and their confinement in a strong magnetic
field**. Further, the LEIBF allows us to extract ion beams from the plasma in the energy range of a few keV to tens of MeV
for novel ion-matter interaction experiments. In this paper, the charge state distribution studies (relevant to gas mixing
effect) of various atomic species at optimized ion source tuning parameters along with results on materials synthesis/

SUSPMF047

modification using ion beams will be discussed.

Horizontal Beam Response at Extraction Conditions at the Heidelberg
Ion-Beam Therapy Centre
Abstract The Heidelberg Ion-Beam Therapy Centre’s
Authors : Edgar Cristopher Cortés García, Eike Feldmeier,synchrotron makes use of the sextupole driven

Thomas Haberer (HIT, Heidelberg)

RF-KO method near the third-order resonance in order toslowly extract the beam that is delivered to the patients.

The horizontal beam response of a coasting beam was studied experimentally and with simulations at extraction conditions
in order to deduce regions of interest for an optimal excitation signal spectrum. Two narrow frequency regions were foundwere the beam reacts coherently. With these information an RF signal was proposed for the resonant slow extraction.

SUSPMF048

IPAC’22

Simulation of Heavy-Ion Beam Losses With Crystal Collimation
Authors : Rongrong Cai, Luigi Salvatore Esposito, Pascal
Dominik Hermes, Stefano Redaelli, Philippe Schoofs (CERN,
Geneva), Francesc Salvat Pujol (CERN, Geneva 23), Roderik
Bruce, Anton Lechner (CERN, Geneva; CERN, Meyrin), Daniele
Mirarchi (CERN, Geneva; The University of Manchester,Manchester), Marco D’Andrea (CERN, Geneva; Univ. degliStudi di Padova, Padova), Jean-Baptiste Potoine (CERN,
Meyrin; IES, Montpellier)

Abstract With the higher stored energy envisioned for
future runs and the challenging fragmentation
characteristic of heavy ion beams in the LHC
compared to proton beams, the need arises for evenmore performing collimation systems. One promisingsolution is crystal channeling, which is the baseline
for heavy ion operation during LHC Run III and the
HL-LHC upgrade. To investigate an optimal configuration
for the collimation system, a well-tested simulation

setup is required. This work uses the implementation of channeling and other coherent effects in the SixTrack-FLUKASUSPMF049

Coupling simulation framework and compares simulated loss patterns with data from previous beam tests.

Algorithm to Mitigate Magnetic Hysteresis in Magnets With Unipolar
Power Supplies
Authors : Jamiel Nasser, Richard Baartman, Oliver Karl Kester,
Spencer Kiy, Thomas Planche, Stephanie Diana Rädel, Olivier
Shelbaya (TRIUMF, Vancouver)

Abstract The effects of hysteresis on the fields producedby magnetic lenses are not accounted for in TRIUMF’s
models of the accelerators. Under certain conditions,such as quadrupoles with unipolar power supplies
operating at low currents, these effects have introduced

significant field errors with consequences upon tranverse tunes. To combat these uncertainties and make the fields more
reproducible and stable, a technique new to TRIUMF has been implemented. This technique ramps the current cyclically
about the desired setpoint to reach a reproducible field that is independent of its history. Results of magnetic measurements
at TRIUMF using this technique are presented, as well as the expected improvements to the accuracy of the beam optics

SUSPMF050

model, particularly for unipolar quadrupoles.

Machine Learning Based Surrogate Model Construction for Optics Matchingat the European XFEL
Abstract Beam optics matching is a daily routine in
Authors : Zihan Zhu, Ye Chen, Matthias Scholz, Sergey Tomin

the operation of an X- ray free-electron laser facility.

(DESY, Hamburg)

Usually, linear optics is employed to conduct the beam
matching in the control room. However, the collective

effects like space charge dominate the electron bunch in the low-energy region which decreases the accuracy of the existing
tool. Therefore, we proposed a scheme to construct a surrogate model with nonlinear optics and collective effects tospeed up the optics matching in the European XFEL injector section. This model also facilitates further research on beam
dynamics for the space-charge dominated beam.

SUSPMF051

IPAC’22

ENUBET’s Multi Momentum Secondary Beam Line
Authors : Elisabetta Giulia Parozzi (Universita Milano Bicocca,
MILANO), Nikolaos Charitonidis (CERN, Geneva), Giulia Brunetti, Francesco Terranova (INFN MIB, MILANO; Universita
Milano Bicocca, MILANO), Fabio Pupilli (INFN- Sez. di Padova,
Padova), Andrea Longhin (INFN- Sez. di Padova, Padova;
Univ. degli Studi di Padova, Padova)

Abstract In order to study the remaining open questions
concerning CP violation and neutrino mass hierarchy,
as well as to search for physics beyond the Standard
Model, future experiments require precise measurementsof the neutrino interaction cross-sections in the GeV/cregime. The absence of a precise knowledge of theneutrino flux currently limits this measurement to a
10-20% uncertainty level. The ENUBET project is

proposing a novel facility, capable of constraining the neutrino flux normalization through the precise monitoring of kaon
decay products in an instrumented decay tunnel. The collaboration has conducted numerous studies using a beam-linewith a central Kaon momentum of 8.5 GeV/c and a ±10% momentum spread. We present here the design of a new
beam-line, broadening the range of Kaons to include momenta of 4, 6, and 8.5 GeV/c, thus allowing ENUBET to explore
cross-sections over a much larger energy range. In this contribution, we discuss the status of this design, the optimization
studies performed, the early results, and the expected performance in terms of kaon and neutrino rates. We also present

SUSPMF052

the first estimations of the background expected to be seen by the experiment.

Wakefield Effects Evaluation on Nanometer Small Beam at KEK-ATF
Authors : Yuki Abe (Sokendai, Ibaraki), Kiyoshi Kubo, Toshiyuki
Okugi, Nobuhiro Terunuma (KEK, Ibaraki; Sokendai, Ibaraki)

Abstract Accelerator Test Facility (ATF) is R&D facility
to evaluate final focus technology for small beamrequired by ILC. The final focus beamline(ATF2) sets
the goal to achieve 37 nm vertical beam size and 41 nm

beam size had been demonstrated. Moreover, a significant intensity dependence on a nanometer beam size was observed
and several studies of the wakefield had been conducted [*,**,***]. ATF2 is a proper beamline for wakefield studies withlow emittance beam and nanometer resolution cavity BPMs and a nanometer beam size monitor. The simulation results
were qualitatively cross-checked with experimental results and showed that the effects of some vacuum components and
BPMs were significant. Further analysis of the wakefield will be done for flexible components (e.g. bellows). An upgradeof the ATF2 beamline is proposed by including minimization of the wakefield sources, to establish technologies for stable

SUSPMF053

nanometer beam.

Design Optimization of 100 mA Superconducting Linac
Authors : Man Yi (IMP/CAS, Lanzhou)

Abstract Beam loss is a critical challenge in the physics
design of high power superconducting proton linacs.
The challenge is even more acute in linacs that featurehigh peak intensity and low energy, which has strong space charge effect and RF nonlinear force. In this paper, we study
how to achieve a high transmission rate for beam halo particles, commonly a major source of beam loss, via beam halo
matching and acceptance optimization. We employ this method of beam loss reduction to improve the physics design ofa high power 100mA superconducting linac which has potential applications in high brightness neutron production.

SUSPMF054

IPAC’22

A Design Study of Injector System for Synchrotron Light Source
Authors : Chanmi Kim, Eun-San Kim, Chong Shik Park (KUS,
Sejong)

Abstract This work presents a design study of a
200 MeV electron linear accelerator consisting of anelectron gun, bunchers, and accelerator structures.
We aimed to design the linac with low emittance andlow energy spread. A coasting beam from the thermionic electron gun is bunched using a series of buncher cavities,
sub-harmonic buncher (SHB), a pre-buncher (PB), and a buncher. The bunched beam is then accelerated to 200 MeV
with 4 cascaded accelerating structures. Two types of SHB cavities with an RF frequency of 500 MHz, elliptical cavity
and coupled cavity, were considered to improve the bunching efficiency. We also investigated constant-gradient andconstant-impedance types of 3 GHz multi-cell traveling wave resonators for following buncher cavities and accelerating
structures. Depending on the type, the geometries of each TWR cavity were determined, and then the electromagnetic
fields were calculated. RF powers and phases of each cavity along this linac system were optimized using beam dynamics
simulation. Furthermore, the beam distributions in the transverse direction are adjusted using solenoid magnets in the

SUSPMF055

low-energy section as well as quad triplets in the high-energy section.

Improved Low-Energy Optics Control for Transverse Emittance Preservation
at the CERN Proton Synchrotron
Authors : Wietse Van Goethem, Foteini Asvesta, Hannes
Bartosik, Alexander Huschauer (CERN, Geneva), Fanouria
Antoniou (CERN, Meyrin)

Abstract Preservation of the transverse emittancesacross the CERN accelerator chain is an important
requirement for beams produced for the Large Hadron
Collider (LHC). In the CERN Proton Synchrotron (PS),high brightness LHC-type beams are stored on a longflat bottom for up to 1.2 seconds. During this storage time, direct space charge effects may lead to resonance crossing
and subsequent growth of the transverse emittances. Previous studies showed an important emittance increase when
the PS working point is moved near integer tune values. Subsequent simulation studies confirmed that this observation iscaused by an interplay of space charge effects and the optics beatings induced by the Low Energy Quadrupoles (LEQ). A
new optics configuration using these quadrupoles to reduce the optics beating and the emittance growth was developed

SUSPMF056

and experimentally validated. The results of simulation and experimental studies are presented in this contribution.

Progress Towards Analytic Modelling of the VFFA
Abstract The Vertical Excursion Fixed-Field Alternating
Authors : Max Emil Topp-Mugglestone (JAI, Oxford)

Gradient Accelerator is a novel concept in Accelerator
Physics with wide- ranging applications across anumber of different fields. In particular, it is being studied as a candidate for next-generation spallation sources, as well as
in the context of rapid muon acceleration. However, the current understanding of the optics of this machine is still limited
due to its unique magnetic fields, which result in strongly coupled optics due to both solenoid and skew quadrupole-likecomponents in the magnetic fields. This poster aims to present first steps at understanding the behaviour of this machinefrom a Hamiltonian perspective, focusing on a large-ring regime such as might be applicable to the design of a muon
collider. Under a set of appropriate approximations, it is now possible to predict the dependence of the tune of such amachine on the input parameters of the lattice, yielding vital first steps towards understanding this type of machine anddeveloping efficient design and optimisation procedures.

SUSPMF057

IPAC’22

Iron Yoke Effects in Quadrupole Magnets for High Rigidity Isotope Beams
Authors : David Greene, Yoonhyuck Choi, Jon DeKamp,
Peter Ostroumov, Mauricio Portillo, John Wenstrom, Ting
Xu (FRIB, East Lansing, Michigan), Shashikant L. Manikonda(AML, Melbourne, Florida)

Abstract Iron-dominated superconducting magnets
are one of the most popular and most used design
choices for superconducting magnetic quadrupoles
for accelerator systems. While the iron yoke and poletips are economic and effective in shaping the field, thelarge amount of iron also leads to certain drawbacks,

namely, unwanted harmonics from the sextupole correctors nested inside of the quadrupole. Additional problems include
the nonlinear field profile present in the high-field regime engendered by the presence of steel, and the mechanical andcryogenic design challenges of the entire iron yoke being part of the cold mass. The presented work discusses theseeffects and challenges by comparing an iron-dominated quadrupole model to an equivalent coil-dominated quadrupolemodel. The comparison of their respective magnetic harmonics, integrated strength, multipole effects, and mechanical

SUSPMF058

challenges demonstrates that the coil-dominated design is a more favorable choice for select accelerator systems.

CW Polarized Positron Beams for 12 GeV CEBAF
Authors : Sami Habet, Ryan Michael Bodenstein, Alex Bogacz,
Joseph Michael Grames, Alicia Hofler, Reza Kazimi,
Yves Raymond Roblin, Riad Suleiman, Amy Sy, Dennis Turner,
Yuhong Zhang (JLab, Newport News, Virginia),Eric Jean-Marie
Voutier (LPSC, Grenoble Cedex), Fanglei Lin (ORNL RAD, Oak
Ridge, Tennessee), Karl William Smolenski (Xelera Research
LLC, Ithaca, New York)

Abstract Positron beams would provide new andmeaningful probes for the experimental program at
the Thomas Jefferson National Accelerator Facility(JLab), including but not limited to future hadronic
physics and dark matter experiments. Criticalrequirements involve generating positron beams with ahigh degree of spin polarization, sufficient intensity anda continuous- wave (CW) bunch train compatible withacceleration to 12 GeV at the Continuous Electron Beam Accelerator Facility (CEBAF). To address these requirements, apolarized positron injector based upon the bremsstrahlung of an intense CW spin polarized electron beam is considered*.
First a polarized electron beam line provides >1 mA of polarized electrons at ~120 MeV to a high-power target for positron
production. Next, a second beam line collects, shapes and aligns the spin of positrons for users. Finally, the positron
beam is matched into the CEBAF acceptance for acceleration and transport to the end stations with energies up to 12
GeV. An optimized layout to provide positrons beams with intensity >100 nA (polarized) or intensity >3 µA (unpolarized)
will be discussed in this poster.

SUSPMF059

IPAC’22

Cooling Performance in a Dual Energy Storage Ring Cooler
Authors : Bhawin Dhital (ODU, Norfolk, Virginia), Yaroslav
Serg Derbenev, David Douglas, Andrew Hutton, He Zhang,
Yuhong Zhang (JLab, Newport News, Virginia), Geoffrey
Arthur Krafft (JLab, Newport News, Virginia; ODU, Norfolk,
Virginia), Fanglei Lin, Vasiliy Morozov (ORNL RAD, Oak
Ridge, Tennessee)

Abstract The longitudinal and transverse emittance
growth in hadron beams due to intra-beam scattering(IBS) and all heating sources would deteriorate theluminosity in a collider. Hence, a strong hadron
beam cooling is required to reduce and preserve theemittance. The cooling of high energy hadron beam
is challenging. We propose a dual energy storagering-based electron cooler that uses electron beam to extract heat away from hadron beam in the cooler ring while electron
beam being cooled themselves by synchrotron radiation damping in the high energy damping ring. In this paper, we present
a possible design of a dual energy storage ring-based electron cooler. Finally, the cooling performance is simulatedusing Jefferson Lab Simulation Package for Electron Cooling (JSPEC) for proton beams at the top energy of 275 GeV

SUSPMF060

for Electron-Ion Collider.

Linac Optics Optimization With Multi-Objective Optimization
Authors : Isurumali Neththikumara (ODU, Norfolk, Virginia),
Ryan Michael Bodenstein, Alex Bogacz (JLab, Newport News,
Virginia), Todd Satogata (JLab, Newport News, Virginia; ODU,
Norfolk, Virginia), Arthur Vandenhoeke (ULB, Bruxelles)

Abstract The beamline design of recirculating linacs
requires special attention to avoid beam instabilities due
to RF wakefields. A proposed high-energy, multi-passenergy recovery demonstration at CEBAF uses a low
beam current. Stronger focusing at lower energies isnecessary to avoid beam breakup(BBU) instabilities,

even with this small beam current. The CEBAF linac optics optimization balances over-focusing at higher energies andbeta excursions at lower energies. Using proper mathematical expressions, linac optics optimization can be achieved withSUSPMF061

evolutionary algorithms. Here, we present the optimization process of North Linac optics using multi-objective optimization.

Modeling a Nb3Sn Cryounit in GPT at UITF
Authors : Sunil Pokharel (ODU, Norfolk, Virginia), Alicia Hofler(JLab, Newport News, Virginia), Geoffrey Arthur Krafft (JLab,
Newport News, Virginia; ODU, Norfolk, Virginia)

Abstract Nb3Sn is a prospective material for future
superconducting RF (SRF) accelerator cavities.The
material can achieve higher quality factors, higher
temperature operation and potentially higher accelerating
gradients (Eacc 96 MV/m) compared to conventional

niobium. In this work, we performed modeling of the Upgraded Injector Test Facility (UITF) at Jefferson Lab utilizing newly
constructed Nb3Sn cavities. We studied the effects of the buncher cavity and varied the gun voltages from 200-500 keV.
We have calibrated and optimized the SRF cavity gradients and phases for the Nb3Sn five-cell cavities energy gains withthe framework of General Particle Tracer (GPT). Our calculations show the beam goes cleanly through the unit. There is
full energy gain out of the second SRF cavity but not from the first SRF cavity due to non-relativistic phase shifts.

SUSPMF062

IPAC’22

Authors : Jens Schaefer, Bastian Haerer, Anke-Susanne Mueller, Alexander Ivanovich Papash, Robert Ruprecht, Marcel
Schuh (KIT, Karlsruhe)

Abstract The compact Storage ring for Accelerator
Research and Technology cSTART is a test facility
for the application of novel acceleration techniquesand diagnostics. The goal is to demonstrate storing
the beam of a Laser Plasma Accelerator (LPA) for

the first time in a compact circular accelerator. Before installing a LPA, the linear accelerator FLUTE will serve as a fullenergy injector for the compact storage ring, providing stable bunches with a length of a few femtoseconds. The transportof the bunches from FLUTE to the storage ring requires a transfer line which includes horizontal, vertical and coupled
deflections which leads to coupling of the dynamics in the two transverse planes. In order to conserve the ultra-short bunch
length during the transport, the transfer line relies on special optics which invokes high and negative dispersion. ThisSUSPMF063

contribution presents dynamic aperture studies based on six-dimensional tracking through the lattice of the transfer line.

Testing the Global Diffusive Behaviour of Beam-Halo Dynamics at the
CERN LHC Using Collimator Scans
Authors : Carlo Emilio Montanari (Bologna University, Bologna;
CERN, Geneva), Armando Bazzani (Bologna University, Bologna),
Massimo Giovannozzi, Stefano Redaelli (CERN, Geneva),
Arkadiusz Andrzej Gorzawski (University of Malta, Msida)

Abstract In superconducting circular particle accelerators,
controlling beam losses is of paramount importancefor ensuring optimal machine performance and an
efficient operation. To achieve the required level ofunderstanding of the mechanisms underlying beamlosses, models based on global diffusion processes

have recently been studied and proposed to investigate the beam-halo dynamics. In these models, the building block of
the analytical form of the diffusion coefficient is the stability-time estimate of the Nekhoroshev theorem. In this paper, thedeveloped models are applied to data acquired during collimation scans at the CERN LHC. In these measurements, thecollimators are moved in steps and the tail population is re-constructed from the observed losses. This allows an estimate

SUSPMF064

of the diffusion coefficient. The results of the analyses performed are presented and discussed in detail.

Third-order Resonance Compensation at the FNAL Recycler Ring
Authors : Cristhian Eduardo Gonzalez-Ortiz (MSU, East
Lansing, Michigan), Peter Ostroumov (FRIB, East Lansing,Michigan), Robert Ainsworth (Fermilab, Batavia, Illinois)

Abstract The Recycler Ring (RR) at the Fermilab
Accelerator Complex performs slip-stacking on 8 GeV
protons, doubling the beam intensity delivered to theMain Injector (MI). At MI, the beam is accelerated

to 120 GeV and delivered to the high energy neutrino experiments. Femilab’s Proton Improvement Plan II (PIP-II) will require
the Recycler to store 50% more beam. Simulations have shown that the space charge tune shift at this new intensity willlead to the excitation of multiple resonance lines. Specifically, this study looks at normal sextupole lines $3 Q_x=76$ and$Q_x+2Q_y=74$, plus skew sextupole lines $3 Q_y=73$ and $2 Q_x+Q_y=75$. Dedicated normal and skew sextupoles
have been installed in order to compensate for these resonance lines. By measuring and calculating the ResonanceDriving Terms (RDT), this study shows how each of the resonance lines can be compensated independently. Furthermore,this study shows and discusses initial investigations into compensating multiple lines simultaneously.

SUSPMF065

IPAC’22

Plateau-Like Accelerating Wakefield for Electron-Witness-Bunch andPlateau-Like Decelerating Wakefield for Driver-Bunch in Plasma Wakefield
Accelerator at High Transformer Ratio
Authors : Roman Ovsiannikov (KhNU, Kharkov), Iryna Pavlovna
Levchuk (Yarovaya), Vasyl I. Maslov, Ivan N. Onishchenko(NSC/KIPT, Kharkov)

Abstract The efficiency of electron acceleration by awakefield, excited in a plasma by an electron bunch, isdetermined by the transformer ratio*. The transformer
ratio approximately can be defined as as the ratio the
maximum accelerating field after after the drive-bunch

to the maximum decelerating field inside drive-bunch. There is also the problem of maintaining the low emittance and low
energy spread of the electron witness-bunch while maintaining the high transformer ratio and the accelerating gradient.
In this report, numerical simulation by the 2d3v code LCODE solves the problem of the identical decelerating wakefield
excitation for the whole long shaped drive-bunch and electron witness-bunch acceleration of low energy spread, small
emittance and high charge by identical accelerating gradient for the whole witness- bunch with high transformer ratio and

SUSPMF066

focusing both bunches**.

Design Optimisation Studies of Azimuthally Modulated RF Cavities
Authors : Laurence Matthew Wroe (JAI, Oxford), Robert Apsimon (Cockcroft Institute, Lancaster), Suzanne L. Sheehy(The University of Melbourne, Melbourne, Victoria)

Abstract In this paper, we discuss the scope andlimitations of azimuthally modulated RF cavities
that support modes with user-specified multipolar
field contributions for practical application in particle
accelerators. We present an example optimisation forcancelling unwanted transverse multipolar components in an accelerating RF cavity, outlining the methodology andevaluating 3D CST simulations, and also an analysis of the conditions governing forbidden and allowed modes in

SUSPMF067

azimuthally modulated cavity designs.

Parallelization of Radia Magnetostatics Code
Authors : Anushka Banerjee (SBU, Stony Brook, New York),
Oleg Chubar (BNL, Upton, New York), Joel Chavanne, GaëlLe Bec (ESRF, Grenoble), Jonathan Edelen, Christopher Hall,
Boaz Nash (RadiaSoft LLC, Boulder, Colorado)

Abstract Radia 3D magnetostatics code has beenused for the design of insertion devices for lightsources over more than two decades. The codeuses the magnetization integral approach that is
efficient for solving permanent magnet and hybrid
magnet structures. The initial version of the Radia

code was sequential, The initial version of the Radia code was sequential, its core written in C++ and interface in the
Mathematica language. This paper describes a new Python-interfaced parallel version of Radia and its applications. The
parallelization of the code was implemented on C++ level, following a hybrid approach. Semi-analytical calculations ofinteraction matrix elements and resultant magnetic fields were parallelized using the Message Passing Interface, whereas
the parallelization of the “relaxation” procedure (solving for magnetizations in volumes created by subdivision) was executedusing a shared memory method based on C++ multithreading. The parallel performance results are encouraging, particularly
for magnetic field calculation post relaxation where a ~600 speedup with respect to sequential execution was obtained.
The new parallel Radia version facilitates designs of insertion devices and lattice magnets for novel particle accelerators.

SUSPMF068

IPAC’22

Investigating the Suppression of the Crab Cavity Noise Induced Emittance
Growth From the Transverse Beam Impedance
Authors : Natalia Triantafyllou, Andrzej Wolski (The Universityof Liverpool, Liverpool), Fanouria Antoniou, Hannes Bartosik,
Philippe Baudrenghien, Xavier Buffat, Rama Calaga, Yannis
Papaphilippou (CERN, Meyrin), Themis Mastoridis (CalPoly,San Luis Obispo, California)

Abstract Crab Cavities are a key component of theHigh Luminosity LHC (HL-LHC) upgrade, as they aim
to minimize the luminosity reduction caused by thecrossing angle. Two superconducting crab cavities
were installed in the Super Proton Synchrotron (SPS) at
CERN in 2018 to test their operation in a proton machinefor the first time. An important point to consider is theincrease in transverse emittance induced by noise in the Low- Level RF (LLRF) system. During the first experimental
campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available
analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse
emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in

SUSPMF069

2021, are discussed.

Effect of the Betatron Coupling on the Beam Transverse Instabilities
Authors : Watanyu Foosang, Alexis Gamelin (SOLEIL,
Gif-sur-Yvette)

Abstract The effect of the betatron coupling on thetransverse instabilities is being studied currently at
SOLEIL since it should modify, possibly increase, theinstability thresholds which could be very low in the caseof SOLEIL Upgrade. The coupling has an influence in particular on the mixing of the damping times, the chromaticities aswell as the transfer of the impedance between the two transverse planes. Consequently, the damping time of the stabilizing
mechanisms and the rise time of the instabilities are modified, so are the instability thresholds. This work presents
simulation results obtained for the SOLEIL upgrade case on the beam transverse dynamics, transverse mode-coupling

SUSPMF070

and head-tail instability in the presence of betatron coupling.

Microbunching Studies for the FLASH2020+ Upgrade Using a Semi- Lagrangian
Vlasov Solver
Authors : Philipp Amstutz, Mathias Vogt (DESY, Hamburg)

Abstract Precise understanding of the
microbunching instability is mandatory for the
successful implementation of a compression strategy

for advanced FEL operation modes such as the EEHG seeding scheme, which a key ingredient of the FLASH2020+
upgrade project. Simulating these effects using particle-tracking codes can be quite computationally intensive as anincreasingly large number of particles is needed to adequately capture the dynamics occurring at small length scales andreduce artifacts from numerical shot-noise. For design studies as well as dedicated analysis of the microbunching instability
semi- Lagrangian codes can have desirable advantages over particle- tracking codes, in particular due to their inherently
reduced noise levels. However, rectangular high-resolution grids easily become computationally expensive. To this end wedeveloped SelaV$_\mathrm{1D}$, a one dimensional semi-Lagrangian Vlasov solver, which employs tree-based domain
decomposition to allow for the simulation of entire exotic phase-space densities as they occur at FELs. In this contribution
we present results of microbunching studies conducted for the FLASH2020+ upgrade using SelaV$_\mathrm{1D}$.

SUSPMF071

IPAC’22

Modeling and Mitigation of Long-Range Wakefields for Advanced Linear
Colliders
Authors : Fabio Bosco, Martina Carillo, Lucia Giuliano, Mauro
Migliorati, Andrea Mostacci, Luigi Palumbo (Sapienza Universityof Rome, Rome), Luigi Faillace, Anna Giribono (INFN/LNF,
Frascati), Enrica Chiadroni, Bruno Spataro, Cristina Vaccarezza(LNF-INFN, Frascati), Obed Camacho (UCLA, Los Angeles),Atsushi Fukasawa, Nathan Majernik, James Rosenzweig(UCLA, Los Angeles, California)

Abstract The luminosity requirements of TeV-classlinear colliders demand use of intense charged beams
at high repetition rates. Such features imply multi-bunch
operation with long current trains accelerated over the
km length scale. Consequently, particle beams are
exposed to the mutual parasitic interaction due to thelong-range wakefields excited by the leading bunches
in the accelerating structures. Such perturbations to the
motion induce transverse oscillations of the bunches,

potentially leading to instabilities such as transverse beam break-up. Here we present a dedicated tracking code thatstudies the effects of long-range transverse wakefield interaction among different bunches in linear accelerators. Being
described by means of an efficient matrix formalism, such effects can be included while preserving short computationaltimes. As a reference case, we use our code to investigate the performance of a state-of-the-art linear collider currently

SUSPMF072

under design and, in addition, we discuss possible mitigation techniques based on frequency detuning and damping.

Beam Lifetime Measurements in Sirius Storage Ring
Authors : Murilo Barbosa Alves, Fernando Henrique de Sá,
Lin Liu, Ximenes Rocha Resende (LNLS, Campinas)

Abstract Sirius is the new storage ring-based 4th
generation synchrotron light source built and operated
by the Brazilian Synchrotron Light Laboratory (LNLS)
at the Brazilian Center for Research in Energy andMaterials (CNPEM). In ultralow emittance storage rings such as Sirius, since the bunch charge density is typically high,the dominant contribution to the beam lifetime is due to large angle scattering between electrons within the same bunch,namely the Touschek effect. We used the strategy of storing simultaneously two single-bunches with different currents
to measure their Touschek lifetime independently of other contributions to the total lifetime, such as gas scattering. The
measurements were carried out in different conditions of transverse coupling, radiofrequency voltage and bunch current
to characterize the dependence of beam lifetime on these parameters and to compare the experimental results with thoseSUSPMF073

expected from theory and simulations for Sirius.

Interplay between Space Charge and Intra-beam Scattering for the CERN Ion
Injectors
Authors : Michail Zampetakis, Foteini Asvesta, Hannes Bartosik,
Yannis Papaphilippou (CERN, Geneva), Fanouria Antoniou(CERN, Meyrin)

Abstract The CERN ion injectors, SPS and LEIR,
operate in a strong space charge and intra-beam
scattering regime, which can lead to degradation of theirbeam performance. To optimize machine performancerequires thus to study the interplay of these two effects

in combined space charge and intrabeam scattering tracking simulations. In this respect, the kinetic theory approach of
intra-beam scattering has been implemented in pyORBIT and benchmarked against analytical models. First results ofcombined space charge and intra-beam scattering simulations for SPS and LEIR are presented in this contribution. The
simulation results are compared with observations from beam measurements.

SUSPMF074

IPAC’22

Studies on the Vertical Half-Integer Resonance in the CERN PS Booster
Authors : Tirsi Prebibaj, Fanouria Antoniou (CERN, Meyrin),
Foteini Asvesta, Hannes Bartosik (CERN, Geneva), Giuliano
Franchetti (GSI, Darmstadt)

Abstract Following the upgrades of the LHC Injectors
Upgrade Project (LIU), the Proton Synchrotron Booster(PSB) at CERN successfully doubled the brightnessof the delivered beams. The dynamic correction of thebeta-beating induced by the injection chicane allowedstable operation closer to the half-integer resonancecontributing to the above achievement. Ideally, injection above the half-integer resonance could further improve thebeam brightness. In this context, a series of studies were initiated in order to characterize the effects of space charge

SUSPMF075

when crossing the half-integer resonance. In this contribution, the first results of these investigations are reported.

Space Charge Analysis for Low Energy Photoinjector
Authors : Martina Carillo, Fabio Bosco, Enrica Chiadroni,
Lucia Giuliano, Mauro Migliorati, Andrea Mostacci, Luigi
Palumbo (Sapienza University of Rome, Rome), Luca Ficcadenti(INFN-Roma, Roma), Luigi Faillace (INFN/LNF, Frascati), Mostafa Behtouei, Bruno Spataro (LNF-INFN, Frascati), Obed
Camacho (UCLA, Los Angeles), Atsushi Fukasawa, James
Rosenzweig (UCLA, Los Angeles, California)

Abstract Beam dynamics studies are performedin the context of a C-Band hybrid photo-injector
project developed by a collab- oration between UCLA/
Sapienza/INFN-LNF/RadiaBeam. These studies aim
to explain beam behaviour through the beam-slice
evolution, using analytical and numerical approaches.
An understanding of the emittance oscillations is
obtained starting from the slice analysis, which allows
correlation of the position of the emittance minima

with the slope of the slices in the transverse phase space (TPS). At the end, a significant reduction in the normalized
emittance is obtained by varying the transverse shape of the beam while assuming a longitudinal Gaussian distribution.
Indeed, the emittance growth due to nonlinear space-charge fields has been found to occur immediately after moment of

SUSPMF076

the beam emission from the cathode, giving insight into the optimum laser profile needed for minimizing the emittance.

Prospects of Ultrafast Electron Diffraction Experiments in Sealab, Longitudinal
Phase-Space Manipulation and Beam Stability
Authors : Benat Alberdi, Ji-Gwang Hwang, Axel Neumann,Jens Voelker (HZB, Berlin), Thorsten Kamps (HU Berlin,
Berlin; HZB, Berlin)

Abstract Ultrafast Electron Diffraction (UED) is a
pump-probe experimental technique that aims toimage the structural changes that happen in a target
structure due to photo- excitation. Development of UED
capabilities is one of the main objectives at Sealab, asuperconducting RF accelerator facility currently being commissioned in Helmholtz-Zentrum Berlin. The main beam-line
is based on the SRF Photoinjector. In order to perform UED experiments, the optimization of temporal and spatial
resolutions are of the utmost importance. These are governed by the minimum achievable bunch length, transverse
emittance and beam stability. The composition of the SRF Photoinjector, which includes a superconducting RF gun andthree superconducting booster cavities, offers superb flexibility to manipulate the longitudinal phase-space of the electron
bunch. At the same time, the CW operation of the accelerator provides an enhanced beam stability compared to warm
guns, together with a MHz repetition rate. This presentation aims to explain the different contributions to the temporaland spatial resolutions and understand the performance limits of the SRF Photoinjector to perform UED experiments.

SUSPMF077

IPAC’22

A Path-Length Stability Experiment for Optical Stochastic Cooling at theCornell Electron Storage Ring
Authors : Samuel Joseph Levenson, Matthew Benjamin Andorf,
Ivan Vasilyevich Bazarov, Vardan Khachatryan, Jared Michael
Maxson, David Rubin, Suntao Wang (Cornell University(CLASSE), Ithaca, New York)

Abstract To achieve sufficient particle delay withrespect to the optical path in order to enable high gain
amplification, the design of the Optical Stochastic
Cooling (OSC) experiment in the Cornell Electron
Storage Ring (CESR) places the pickup (PU) andkicker (KU) undulators approximately 80 m apart.

The arrival times at the KU of particles and the light they produce in the PU must be synchronized to an accuracy of lessthan an optical wavelength, which for this experiment is 780 nm. To test this synchronization, a planned demonstration of
the stability of the bypass in CESR is presented where, in lieu of undulators, an interference pattern formed with radiationfrom two dipoles flanking the bypass is used. In addition to demonstrating stability, the fringe visibility of the pattern isrelated to the cooling ranges, a critical parameter needed for OSC. We present progress on this stabilization experiment
including the design of a second-order isochronous bypass, as well as optimizations of the Dynamic Aperture (DA) and

SUSPMF078

injection efficiency.

Electron Beam Optimization for FLASH Radiotherapy Experiment at Chiang
Mai University
Authors : Kanlayaporn Kongmali, Nopadol Kangrang, Sakhorn
Rimjaem, Jatuporn Saisut, Chitrlada Thongbai (Chiang Mai
University, Chiang Mai), Monchai Jitvisate (Suranaree
University of Technology, Nakhon Ratchasima)

Abstract At present, one of diseases that kill many
people worldwide is cancer. The FLASH radiotherapy(RT) is a promising cancer treatment under study.
It involves the fast delivery of radiotherapy at muchhigher dose rates than those currently used in clinicalpractice. The very short time of exposure leads to thedestruction of the cancer cells, while the nearby normal cells are less damaged as compared with conventional RT. This
work focuses on study of FLASH-RT experiment using electron beams produced from the accelerator system at the
PBP-CMU Electron Linac Laboratory. The structure and properties of our electron pulses with microbunches in picosecond
time scale and macropulses in microsecond time scale match well to FLASH-RT requirement. To optimize the condition
for experiment, the electron beam simulations are performed by varying energy, charge and bunch length. The study
results show that the beams with energy of 6 - 25 MeV, macropulse of 1 - 4 ¿s, microbunch of 0.3 -1 ps, variable highcurrent, and low emittance are well suit for FLASH-RT experiment. The optimized electron beam properties from thisstudy will be used as the guideline for experiment preparation.

SUSPMF079

IPAC’22

Relativistic Space-Charge Force Calculation by Interpolation-Based Treecode
Authors : Yi-Kai Kan (DESY, Hamburg), Franz Xaver Kaertner(Deutsches Elektronen Synchrotron (DESY) and Center for
Free Electron Science (CFEL), Hamburg), Sabine Le Borne,
Daniel Ruprecht, Jens-Peter Zemke (Hamburg University ofTechnology, Hamburg)

Abstract Space-charge effects are of great importancein particle accelerator physics. In the computationalmodeling, tree-based methods are increasingly usedbecause of their effectiveness in handling nonuniform
particle distributions and/or complex geometries.
However, they are often formulated using an electrostaticforce which is only a good approximation for low energy

particle beams. For high energy, i.e., relativistic particle beams, the relativistic interaction kernel may need to be considered
and the conventional treecode fails in this scenario. In this work, we formulate a treecode based on Lagrangianinterpolation for computing the relativistic space-charge field. Two approaches are introduced to control the interpolation error.
The first approach is based on the transformation of the particle beam to the rest-frame where the conventiona
admissibility condition can be used. In the second approach, a modified admissibility condition is proposed for which
the treecode can be used directly in the lab-frame. Numerical simulation results using both methods will be compared

SUSPMF080

and discussed.

Spin-Tracking Simulations in a COSY Model Using Bmad
Authors : Maximilian Vitz (FZJ, Jülich)

Abstract The matter-antimatter asymmetry might beunderstood by investigating the EDM (Electric Dipole
Moment) of elementary charged particles. A permanent

EDM of a subatomic particle violates time reversal and parity symmetry at the same time and would be, with the currently
achievable experimental accuracy, an indication for further CP violation than established in the Standard Model. The
JEDI-Collaboration (Jülich Electric Dipole moment Investigations) in Jülich has performed a direct EDM measurement for
deuterons with the so called precurser experiments at the storage ring COSY (COoler SYnchrotron). In order to understandthe measured data and to disentangle an EDM signal from systematic effects, spin tracking simulations in an accurate
simulation model of COSY are needed. Therefore a model of COSY was implemented using the software library Bmad.
Systematic effects were considered by including element misalignments, effective dipole shortening and steerer kicks.
These effects rotate the invariant spin axis additional to the EDM and have to be analyzed and understood. The mostSUSPMF081

recent spin tracking results as well as the methods to find the invariant spin axis will be presented.

Studying Instabilities in the Canadian Light Source Storage Ring Using theTransverse Feedback System
Authors : Stephen Martens (University of Saskatchewan,
Saskatoon), Drew Bertwistle, Mark James Boland (CLS,
Saskatoon, Saskatchewan)

Abstract The Transverse Feedback system at the
Canadian Light Source can identify, categorize, andmitigate against periodic instabilities that arise in thestorage ring beam. By quickly opening and closing

the feedback loop, previously mitigated instabilities will be allowed to grow briefly before being damped by the system.
The resulting growth in the beam oscillation amplitude curve can be analyzed to determine growth/damp rates and modesof the coupled bunch oscillations. Further measurements can be collected via active excitement of modes rather thanpassive growth. These Grow/damp and Excite/Damp curves have been collected and analyzed for various storage ring
beam properties, including beam energy, machine chromaticity, and in-vacuum insertion device gap widths.

SUSPMF082

IPAC’22Development of a New Clusterization Method for the GEM-TPC With Uranium
Projectiles
Authors : Minna Luoma, Francisco Garcia, Raimo Turpeinen(HIP, University of Helsinki), Tobias Blatz, Holger Flemming,
Klaus Götzen, Christos Karagiannis, Nikolaus Kurz, Sven
Loechner, Chiara Nociforo, Christian Joachim Schmidt, Haik
Simon, Bernd Voss, Peter Wieczorek, Martin Winkler (GSI,
Darmstadt), Davit Chokheli (Georgian Technical University,
Tbilisi), Tuomas Grahn, Sami Rinta-Antila (JYFL, Jyvaskyla)

Abstract The Facility for Antiproton and Ion Research
FAIR, in Darmstadt Germany, will be one of the largest
accelerator laboratories worldwide. The Superconducting
FRagment Separator (Super- FRS)* is one of its
main components. The Super-FRS can produce,
separate and deliver high-energy radioactive beams
with intensities up to 1e11 ions/s, covering projectiles
from protons up to uranium and it can be used as anindependent experimental device. The Gas Electron

Multiplier-based Time Projection Chambers (GEM-TPC) in twin configuration is a newly developed beam tracking detector
capable of providing spatial resolution of less than 1 mm with a tracking efficiency close to 100% at 1 MHz counting rate.
The GEM-TPC (HGB4) was tested at the FRagment Separator (FRS), with 238U beam at 850 MeV/u. A new clusterization
method was developed, for the first time and used for an analysis. This method allowed to access to waveforms of each strip

SUSPMF083

signal within a single trigger in an event-by-event basis. The procedures involved in this method will be shown in details.

Characterization of the Electron Beam Visualization Stations of the ThomX
Accelerator
Authors : Alexandre Moutardier, Christelle Bruni, Iryna
Chaikovska, Sophie Chancé, Nicolas Delerue, Ezgi Ergenlik,
Viacheslav Kubytskyi, Hugues Monard (Université Paris-Saclay,
CNRS/IN2P3, IJCLab, Orsay)

Abstract We present the electron beam visualization
stations of the ThomX Accelerator and present firstmeasurement of their performances during the ThomX
commissioning. ThomX is a 50- MeV-electron accelerator
prototype which will use Compton backscattering to
generate a high flux of hard x-rays. To characterize

the beam an arm with several screens can be inserted in the beam trajectory. The screens available are a YAG:Ce screen,
an Optical Transition Radiation (OTR) screen, a sapphire screen and a calibration target. The optical system is based oncommercial lenses that have been reverse-engineered. The magnification of the optical system can be adjusted remotelyusing a motor and the lens can also be focused remotely. We report on the overall performances of the station as measured
during the first steps of beam commissioning and on the optical system remote operations.

SUSPMF084

IPAC’22

Single-Shot Time-Stretch Electro-Optic Sampling at the ELBE Coherent THz
CDR Source
Authors : Christelle Hanoun, Serge Bielawski, Clement Evain,
Eléonore Roussel, Christophe Szwaj (PhLAM/CERLA,
Villeneuve d’Ascq), Pavel Evtushenko, Sergey Kovalev, Michael
Kuntzsch, Anton Ryzhov, Christof Schneider (HZDR, Dresden)

Abstract Electro-optic sampling is a powerful diagnostic
that is widely used for characterizing longitudinal
electron bunch properties. It consists of recording theelectric field created by the bunch, using an electro-optic
crystal and a probe femtosecond laser. However
several challenges still exist for achieving at the sametime a large bandwidth, a long acquisition window, and single- shot operation at high repetition rate. Here we investigate
a new measurement strategy that aims at high repetition rate (up to tens of millions of traces per second when needed)using the so- called photonic time-stretch technique, and that is also capable of high bandwidth by using the the recently
introduced Diversity Electro-Optic Sampling (DEOS)*. We present the first tests of this design using THz pulses generated

SUSPMF085

by the Coherent Diffraction Radiation (CDR) source of ELBE, at Helmholtz- Zentrum Dresden-Rosedorf (HZDR).

Transverse Excitation and Applications for Beam Control
Authors : Philipp Niedermayer, Rahul Singh (GSI, Darmstadt)

Abstract Transverse excitation of stored particle beams
is required for a number of applications in accelerators.
Using a time-varying, transverse electric field with adedicated frequency spectrum, the amplitude and coherence of betatron oscillations can be increased in a controlledmanner. This allows for determination of the betatron tune from turn-by-turn position measurements, control of transverse
beam shapes, as well as extraction of stored beams. For studies of beam excitation, a flexible signal generator is being
developed. It is planned to be a multi-purpose device for applications in beam diagnostics and control. An approach witha software-defined radio (SDR) is chosen, which allows for configurable signal characteristics and tuneable spectra. To
determine appropriate excitation spectra, studies of particle dynamics in presence of excitation are being carried out.
Nonlinear fields are also incorporated to account for beam extraction conditions, which affect the oscillation frequency

SUSPMF086

spectra due to transient detuning effects compared to the linear case.

Comparative Study of Broadband Room Temperature THz Detectors for Highand Intermediate Frequency Response
Authors : Rahul Yadav, Sascha Preu (IMP, TU Darmstadt,
Darmstadt), Andreas Penirschke (THM, Friedberg)

Abstract Room temperature terahertz (THz) detectors
based on Field effect transistors (FETs) and Zero-Bias
Schottky diodes (SD) are prominent members for the
temporal-spatial characterization of the picosecond

scale pulses generated at particle accelerators. However, it has been observed that post detection electronics currently
limit the performance. The comparative study of THz detectors both at higher and intermediate frequency is done
to understand their frequency response. The investigation is carried out using table top THz systems and commerciallyavailable sources. In this paper we present high frequency and intermediate frequency (IF) response of FETs andZero-Bias Schottky THz detectors. Obtained IF frequency results are helpful for understanding and designing the optimized
IF circuitry to go higher IF bandwidths.

SUSPMF087

IPAC’22

Electro-Optical Bunch Diagnostics Using an Optimized Laser Spectrometer
Authors : Carsten Mai, Marcel Kebekus, Shaukat Khan, Vivek
Vijayan (DELTA, Dortmund), Edmund Blomley, Erik
Bründermann, Michele Caselle, Stefan Funkner, Anke-Susanne
Mueller, Gudrun Niehues, Micha Reissig, Johannes Leonhard
Steinmann, Christina Widmann (KIT, Karlsruhe)

Abstract With electro-optical spectral decoding (EOSD)
ultra-short temporal bunch structures can be diagnosedin single-shot acquisition. The technique uses abunch-induced modulation of the spectrum of areference laser pulse. At DELTA, the 1.5-GeV electron
storage ring operated as a synchrotron light source by

TU Dortmund University in Germany, an energy modulation of a short slice of the electron bunch is generated in alaser-electron interaction. Converting the energy modulation to a density modulation allows the coherent emission ofultrashort vacuum ultraviolet pulses as well as short pulses in the THz regime. A setup based on EOSD to analyze thetemporal profile of the modulated bunches is currently under development in Dortmund. For the analysis of the laser pulse
spectrum with high resolution, recently, two different laser spectrometers for EOSD setups were commissioned.
The spectrometers were tested using the near- field EOSD setup at the KIT storage ring KARA (Karlsruhe Research
Accelerator) in short-bunch mode. The acquisition of the laser spectra was performed with the ultra-fast line-array detector

SUSPMF088

KALYPSO. First data measured at KARA using the new diagnostics are presented.

Authors : Sonja Jaster-Merz, Reinhard Brinkmann, Florian
Burkart, Thomas Vinatier (DESY, Hamburg), Ralph Wolfgang
Assmann (DESY, Hamburg; LNF-INFN, Frascati)

devices, or perform autonomous accelerator studies. For such applications, it is advantageous to have a complete anddetailed knowledge of the beam properties. Tomographic methods have shown to be a key tool for beam phase spacereconstruction. Based on these techniques, a novel diagnostics method is being developed to resolve the full 5-dimensional
phase space (x,x’,y,y’,z) of bunches including their transverse and longitudinal distributions and correlations. In simulation
studies, this method shows an excellent agreement between the reconstructed and the original distribution for all five

SUSPMF089

planes.Here, the 5-dimensional phase space tomography method is presented using a showcase simulation study at ARES.

Comparative Study of Broadband Room Temperature THz Detectors for Highand Intermediate Frequency Response
Authors : Youming Deng (SINAP, Shanghai), Yongbin Leng,
Xingyi Xu (SSRF, Shanghai)

Abstract These will cause transient beam loading
effects along the bunch train. A passive third harmonic
cavity was installed at SSRF in July 2021 during II
renovation. Based on a high-resolution bunch-by-bunch

three dimensional measurement system, the beam loading effect of third harmonic cavity with different currents and fillpattern was observed and verified. Compared with the traditional longitudinal diagnostics tools, such as camera, thesystem has higher measurement accuracy and can capture and record much longer data. Moreover, the bunch charge
and three-dimensional position can be measured simultaneously by the system. By correlation analysis, the difference
coming from bunch parameters can be removed, which makes the beam loading effects more apparent. With the help of
the system, the key parameters such as the synchronous phase, synchronous tune and damping parameter are observed
and analyzed. This will help the scholars of SSRF and other accelerators with harmonic cavities to adjust and optimize
the parameters of harmonic cavities and conduct relevant beam dynamics research.

SUSPMF090

IPAC’22

Analysis of Synchronous Oscillation Damping of Storage Ring Based on
Wavelet Analysis Method
Authors : Xing Yang (SINAP, Shanghai), Xingyi Xu (SINAP,
Shanghai; University of Chinese Academy of Sciences, Beijing),
Yongbin Leng (SSRF, Shanghai)

Abstract The synchronous oscillation damping of thestorage ring of accelerator equipment is an importantpart of accelerator research. In the past analysis, theprocess was regarded as a superposition of a sinefunction and an exponential decay function. However,further analysis showed that the two fixed parameters Function superposition cannot describe all the physical information.
The frequency of the sine function and the attenuation factor of the exponential decay function will change significantly
over time. In this article, the change of this parameter over time is studied, and the data of the Shanghai Light Source

SUSPMF091

storage ring is analyzed using this method, and some results are obtained.

Study of Beam Loss Localization With a Cherenkov Beam Loss Monitor in the
CLEAR Facility at CERN
Authors : Sara Benitez Berrocal (CERN, Geneva 23), Pierre
Korysko (CERN, Geneva), Ewald Effinger, Jose Carlos Esteban
Felipe, Wilfrid Farabolini, Anders Toft Lernevall, Belen
Salvachua (CERN, Meyrin), Minsi Chen (University of
Huddersfield, Huddersfield)

Abstract A Cherenkov Beam Loss Monitor prototype,based on optical fibers, is being developed in order
to measure beam losses in the CERN Super Proton
Synchrotron. Several testing campaigns have beenplanned to benchmark the simulations of the systemand test the electronics in CLEAR test facility. During
the first campaign*, the Cherenkov light capture

phenomenon and the photodetector characterization were studied. Cherenkov Beam Loss monitors are detectors capableof monitoring losses along long distances continuously. The localization of the particle losses shower, with a high longitudinal
resolution is calculated from the timing resolution of the signal generated by the photosensors coupled at both ends of the

SUSPMF092

optical fiber. The experimental results of an OBLM installed in CLEAR facility are reported in this paper.

Linearity and Response Time of the LHC Diamond Beam Loss Monitors in the
CLEAR Beam Test Facility at CERN
Authors : Sara Morales Vigo (CERN, Geneva 23; Cockcroft
Institute, Warrington, Cheshire; The University of Liverpool,
Liverpool), Wilfrid Farabolini (CERN, Geneva; CEA-DRF-IRFU,), Luke Aidan Dyks, Pierre Korysko (CERN, Geneva; Oxford
University, Oxford, Oxon), Eva Calvo Giraldo, Ewald Effinger,
Anders Toft Lernevall, Belen Salvachua, Christos Zamantzas(CERN, Meyrin), Carsten Peter Welsch, Joseph Wolfenden(Cockcroft Institute, Warrington, Cheshire; The University ofLiverpool, Liverpool)

Abstract Chemical Vapour Deposition (CVD) diamonddetectors have been tested during the Run 2 operation
period (2015-2018) as fast beam loss monitors for the
Beam Loss Monitoring (BLM) system of the Large
Hadron Collider (LHC) at CERN. However, the lackof raw data recorded during this operation period
restrains our ability to perform a deep analysis of theirsignals. For this reason, a test campaign was carriedout at the CLEAR beam test facility at CERN withthe aim of studying the linearity and response time ofthe diamond detectors against losses from electron beams of different intensities. The signal build-up from multi-bunchedelectron beams was also analyzed. The conditions and procedures of the test campaign are explained, as well as themost significant results obtained.

SUSPMF093

IPAC’22

Energy Spectrum and Emittance Measurements of Electron Beam for
Producing MIR-FEL at PBP-CMU Electron Linac Laboratory
Authors : Pitchayapak Kitisri, Kittipong Techakaew (Chiang
Mai University, Chiang Mai), Sakhorn Rimjaem (Chiang Mai
University, Chiang Mai; ThEP Center, Bangkok)

Abstract At the PBP-CMU Electron Linac Laboratory,
we aim to produce a mid-infrared free-electron laser(MIR-FEL) for pump-probe experiments in the future.
The electron beam is generated from a radiofrequency(RF) thermionic gun with a 1.5-cell cavity before goingto an alpha magnet. In this section, the beam is filtered out by using energy slits. The survived beam is then accelerated
by an RF linear accelerator (linac) with 86 cylindrical cells to get higher energy. This work focuses on the measurements ofenergy spectrum and emittance of electron beam for producing the MIR-FEL. Since our bunch compressor (BC) is achromat
system, the spectrum of electron beam is measured before the beam travels to the BC by using a dipole and a faraday
cup with a slit. After the BC, the transverse emittance is measured with the quadrupole scan technique before it travels
to the undulator. The Astra code is used to investigate all aforementioned processes as well as to design the measuringsystems. The design results including systematic error of the measuring systems will be presented in this contribution.

SUSPMF094

These results can guide us for the system construction as well as the beam operation guiding.

Systematic Study of Measuring Systems for Electron Beam Energy,
Energy Spread and Emittance of the Accelerator System at the PBP-CMU
Electron Linac Laboratory
Authors : Kittipong Techakaew, Sakhorn Rimjaem (Chiang
Mai University, Chiang Mai)

Abstract The linear accelerator system at the
PBP-CMU Electron Linac Laboratory is used to produce
electron beam with suitable properties for generating
coherent THz radiation and MIR FEL. Optimization ofmachine parameters to produce short electron bunches with low energy spread and low transverse emittance was focusedin this study. We conducted ASTRA simulations including 3D space charge algorithm and 3D field distributions for RF gun
and all magnets to develop measuring systems. Electron beam energy and energy spread were investigated downstream
the RF gun and the linac using an alpha magnet and a dipole spectrometer, respectively. The transverse beam emittance
was studied using the quadrupole scan technique. By filtering proper portion of electrons before entering the linac, thebeam with average energy of 20 MeV and energy spread of 0.1- 1% can be achieved for a bunch charge of 100 pC.
The systematic error is less than 10% for measuring average energy and energy spread while it is less than 31% formeasuring emittance when placing the screen of at least 1.0 m behind the scanning quadrupole magnet. The results ofthis study were used to develop the measuring setups in our system.

SUSPMF095

IPAC’22

A Beam Position Monitor for Electron Bunch Detection in the Presence of aMore Intense Proton Bunch for the AWAKE Experiment
Authors : Collette Pakuza, Philip Burrows (JAI, Oxford; Oxford
University, Oxford, Oxon), Roberto Corsini, Wilfrid Farabolini,
Michal Krupa, Thibaut Lefevre, Stefano Mazzoni, Eugenio
Senes, Manfred Wendt (CERN, Geneva)

Abstract The Advanced Proton Driven Plasma Wakefield
Experiment (AWAKE) at CERN uses 6 cm longproton bunches at 400 GeV beam energy, extracted
from the Super Proton Synchrotron (SPS) to drive
high gradient plasma wakefields for the accelerationof electron bunches to 2 GeV within 10 meter length. Knowledge and control of the position of both beams is crucial for theoperation of the experiment. Whilst the current electron beam position monitoring system at AWAKE can be used in theabsence of the proton beam, the proton bunch signal dominates when both particle bunches are present simultaneously.
A new technique based on the generation of Cherenkov diffraction radiation (ChDR) in a dielectric material placed in close
proximity to the particle beam has been designed to exploit the large bunch length difference of the particle beams at
AWAKE, 200 ps for protons versus a few ps for electrons, such that the electron signal dominates. Hence, this techniquewould allow for the position measurement of a short electron bunch in the presence of a more intense but longer proton

SUSPMF096

bunch. The design considerations, numerical analysis and plans for tests at the CLEAR facility at CERN will be presented.

Simulation of Concrete Shielding Activation for Proton Therapy Systems
Using BDSIM and FISPACT-II
Authors : Eliott Ramoisiaux, Eustache Gnacadja, Nicolas
Pauly, Robin Tesse, Marion Vanwelde (ULB, Bruxelles), Cédric
Hernalsteens (CERN, Meyrin; ULB, Bruxelles), William Shields(JAI, Egham, Surrey), Stewart Boogert, Laurence James Nevay(Royal Holloway, University of London, Surrey)

Abstract Proton therapy systems are used worldwide
for patient treatment and fundamental research.
A well-known drawback is the secondary particles
generation when the beam interacts with the energy
degrader. Interactions can also occur at undesirable
locations along the transport beamline. For compact
systems, this poses new challenges for the shielding

design and the activation computation. We propose a novel methodology to seamlessly simulate all the processes relevant
for the evaluation of the activation. A realistic model of the system is developed using Beam Delivery Simulation (BDSIM),a Geant4-based particle tracking code that allows a single model to simulate primary and secondary particle tracking aswell as all particle- matter interactions. The secondary particles fluxes extracted from the simulations are given to the
FISPACT-II code that computes the activation by solving the rate equations. This approach is applied to the Ion Beam
Applications (IBA) Proteus®ONE (P1) system and the shielding of the proton therapy research centre of Charleroi, Belgium.
Results show the evolution of the clearance level and the long-lived nuclides concentrations through the facility lifespan.

SUSPMF097

IPAC’22

Vacuum Control System Upgrade for ALPI Accelerator
Authors : Giovanni Savarese, Loris Antoniazzi, Damiano
Bortolato, Andrea Conte, Fabio Gelain, Davide Marcato, Carlo
Roncolato (INFN/LNL, Legnaro (PD))

Abstract The vacuum system of ALPI accelerator
includes about 40 pumping groups based onturbomolecularpumps. The instrumentation of theaccelerators complex is mainly the one installed in 90s,
with consequent maintenance issues. The control andsupervision systems were developed in the same period by an external company, which produced custom solutions for
the HW and SW parts. Control devices are based on custom PLCs, while the supervision system is based on C and C#.
The communication between the field and the supervisor is composed of multiple levels: RS-232 standard is used to transfer
control parameter from the field devices up to custom multiplexers; RS- 485 transmission is used from the multiplexers to
two PC servers covering different sections of the installation; while Ethernet, is used to connect the servers and the operation
console. Obsolescence and rigidity of the system, deficit of spare parts and impossibility of reparation or modification
without external support, required a complete renovation of the vacuum system and relative controls in the next years.

SUSPMF098

This paper describes the adopted strategy and the implementation status.

KEK LUCX Facility Laser-to-RF&RF-to-RF Stability Study and Optimization
Authors : Konstantin Popov (Sokendai, Ibaraki), Alexander
Aryshev, Nobuhiro Terunuma, Junji Urakawa (KEK, Ibaraki)

Abstract KEK LUCX facility* is a linear accelerator
devoted to the beam instrumentation R&Ds for present
and future accelerator systems and colliders including
ILC. According to the ILC TDR**, it is necessary toachieve RF-gun Laser-to-RF&RF-to-RF phase stability of 0.35°(RMS) and amplitude stability of 0.07%(RMS) with
implementation of the Digital LLRF feedback based on commercially available FPGA board and digital trigger system.
As the first step to achieve ILC stability level at KEK-LUCX facility, present Laser-to-RF&RF-to-RF phase and amplitude
jitters were measured using time- and frequency-domain techniques. After that, jitter influence on beam parameters after
RF-gun and main solenoid magnet was simulated with ASTRA tracking code*** and results were cross-checked during
LUCX facility beam operation. Finally, stable digital trigger system and digital LLRF feedback based on SINAP EVG&EVR
and RedPitaya SIGNALlab- 250 modules were implemented. This report demonstrates the results of Laser-to-RF&RF-to-RFphase and amplitude jitter measurements cross-checked with ASTRA simulation and real beam parameters measurements

SUSPMF099

before and after LUCX facility stabilization.

Machine Learning-Based Control for HoM Reduction and EmittancePreservation in a TESLA-Type Cryomodule at FAST
Authors : Jorge Alberto Diaz Cruz (SLAC, Menlo Park, California;
UNM-ECE, Albuquerque), Dean Richard Edstrom, Alex Lumpkin,
Randy Michael Thurman-Keup (Fermilab, Batavia, Illinois),
Auralee Edelen, Bryce Jacobson, John Sikora (SLAC, Menlo
Park, California)

Abstract Low emittance electron beams are of highimportance at facilities like the Linac Coherent Light
Source II (LCLS-II) at SLAC. Emittance dilution effects due
to off-axis beam transport or a TESLA-type cryomodule(CM) have been shown at the Fermilab Accelerator
Science and Technology (FAST) facility. The results

showed the correlation between the electron beam-induced cavity high-order modes (HOMs) and bunch-by-bunch centroid
slewing and oscillation downstream of the CM. Mitigation of emittance dilution can be achieved by reducing the HOM
signals. Here we present a Machine Learning-based controller for HOM signal reduction. The control actuators are thesteering magnets, vertical and horizontal, upstream of the CM. Results of the controller performance at the FAST facility
are presented. The preliminary results presented here will inform the LCLS-II injector commissioning and will serve as aprototype for HOM reduction and emittance preservation.

SUSPMF100

IPAC’22

A Novel Method for Detecting Anomalous Loss Patterns in the LHC
Authors : Loic Coyle, Frederic Blanc, Tatiana Pieloni (EPFL,
Lausanne), Daniele Mirarchi (CERN, Geneva), Anton Lechner,
Matteo Solfaroli Camillocci, Jorg Wenninger (CERN, Meyrin)

Abstract Understanding and mitigating particle losses
in the Large Hadron Collider (LHC) is essential forboth machine safety and efficient operation. Abnormal
loss distributions are telltale signs of abnormal beam
behaviour or incorrect machine configuration.

By leveraging a novel data-driven method of detecting anomalous loss distributions during machine operation has beendeveloped. An unsupervised neural network anomaly detection model was trained on operational, stable beam, Beam
Loss Monitor (BLM) data acquired during the operation of the LHC. This model is capable of successfully identifying
anomalous events, including Unidentified Falling Object (UFO) loss showers that have previously gone undetected withthe currently implemented UFO detection algorithm. Unsupervised data-driven models, such as the one presented, could
lead to significant improvements in the autonomous labelling of abnormal loss distributions, ultimately bolstering the everSUSPMF101

ongoing effort towards improving the understanding and mitigation of these events.

Novel Approaches for Classification and Forecasting of Time Series in Particle
Accelerators
Authors : Sichen Li, Andreas Adelmann, Jochem Snuverink(PSI, Villigen PSI)

Abstract Particle accelerator interruptions, calledinterlocks, lead to abrupt operational changes and asubstantial loss of beam time despite being necessary
safety measures. Novel time series classification

approaches are applied to decrease beam time loss in the High- Intensity Proton Accelerator complex by forecasting
interlock events. The forecasting is performed through binary classification of single timestamps as well as windows ofmultivariate time series, with methods ranging from Lasso models based on statistical Two Sample Test, to Recurrence
Plots followed by Convolutional Neural Network*. A continuous evaluation metric, Beam Time Saved in any given time,is established with preliminary experiments showing that interlocks could be circumvented by reducing the beam current.
Preliminary results show that the interlock-to-stable classifier can potentially increase the beam time by up to 6 minutes

SUSPMF102

in a day.

Electron Temperature Measurements in a Hydrogen-Filled Capillary
Authors : Sahar Arjmand (INFN/LNF, Frascati)

Abstract The research concerns experimental
and theoretical studies on a plasma source forplasma-based accelerators (PBAs). The interest forcompact accelerators , overcoming the gigantism of theconventional (RF) accelerators, is growing in High Energy Physics. The accelerating gradients of such plasma-based
devices can attain the GV/m scale. The activity of the SPARC_LAB test-facility concerns the development of theabove-mentioned devices, based on gas-filled capillary. Several inlets feed the capillary with a neutral gas (Hydrogen),which is ionized by a high-voltage (HV) discharge. Electron density and temperature have been measured as a functionof time through the Stark broadening profiles of suitable emission lines.

SUSPMF103

IPAC’22

Systematic Investigation of Flux Trapping Dynamics on Samples
Authors : Felix Kramer, Sebastian Keckert (HZB, Berlin),
Oliver Kugeler (BESSY GmbH, Berlin; HZB, Berlin), Jens
Knobloch (BESSY GmbH, Berlin; HZB, Berlin; University ofSiegen, Siegen)

Abstract Trapped magnetic flux in superconducting
cavities can significantly increase the surface
resistance, and thereby limiting their performance. To
reduce trapped flux in cavities, a better understandingof the fundamental mechanism of flux trapping is vital.

With our newly developed system we measure magnetic flux density at 15 points just above a niobium sheet of dimensions(100 x 60 x 3)mm with a time resolution of up to 2 ms. This setup allows us to control parameters like the temperature
gradient, and cooldown rate independently of each other, as well as the magnitude and direction of an external magnetic
field. We present data gathered of a single crystal sample as well as ¿large-grain¿ samples consisting of two grains with agrain boundary in the middle. Our data suggests that not only the temperature gradient but also the cooldown rate has an

SUSPMF104

effect on trapped flux. Also there seems to be a non-trivial relationship between trapped flux and magnitude of applied field.

Cavity Designs for the Ch3 to Ch11 and Bellow Tuner Investigation of theSuperconducting Heavy Ion Accelerator Heliac
Authors : Thorsten Conrad, Marco Busch, Holger Podlech,
Malte Schwarz (IAP, Frankfurt am Main), Markus Basten,
Manuel Heilmann, Anna Rubin, Alexander Schnase, Stepan
Yaramyshev (GSI, Darmstadt), Winfried A. Barth, Florian
Dirk Dziuba (GSI, Darmstadt; HIM, Mainz), Viktor Gettmann,
Thorsten Kuerzeder, Simon Lauber, Julian Arthur List, Maksym
Miski-Oglu (HIM, Mainz), Kurt Aulenbacher (HIM, Mainz; IKP,
Mainz)

Abstract New CH-DTL cavities designs of the planned
Helmholtz Linear Accelerator (HELIAC) are developed incollaboration of HIM, GSI and IAP Frankfurt. The linac,
operated in cw-mode with a final energy of 7.3 MeV/u,
is intended for various experiments, in particular withheavy ions at energies close to the Coulomb barrier
for research on SHE. Twelve sc CH cavities areforeseen, divided into four different cryostats. Eachcavity will be equipped with dynamic bellow tuner.

After successful beam tests with CH0, CH3 to CH11 are being designed. Based on the experience gained so far,
optimization will be made, which will lead to both an increase in performance in terms of reducing the peak fields limitingsuperconductivity and a reduction in manufacturing costs and time. In order to optimize manufacturing, attention was paid
to design many parts of the cavity, such as lids, spokes, tuner and helium shell, with the same geometrical dimensions. In
addition, a tuner test rig was developed, which will be used to investigate the mechanical properties of the bellow tuner.

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For this purpose, different simulations were made in order to realize conditions as close as possible to reality in the test rig.

A New High Vacuum Furnace for SRF R&D
Authors : Rezvan Ghanbari, Christopher Bate, Marc Wenskat(DESY, Hamburg), Wolfgang Carl Albert Hillert (University of
Hamburg, Hamburg)

Abstract A new vacuum furnace has been designed
and purchased by the University of Hamburg and isoperating in an ISO5 cleanroom. This furnace cananneal single-cell TESLA cavities, made of Niobium,
at temperatures up to 1000°C and under a pressureof less than 10-7mbar or in a nitrogen atmosphere of up to 10- 2mbar. We will lay out the underlying design ideas, based on
the gained experience from our previous annealing research, and present the commissioning of the furnace itself. Additionally,
we will show for the first time the results of sample and cavity tests after annealing in the furnace. This will be accompanied
by an overview of the intended R&D process and scientific questions to be addressed.

SUSPMF106

IPAC’22

Commissioning of a New Magnetometric Mapping System for SRF Cavity
Performance Tests
Authors : Jonas Christian Wolff, Juergen Eschke, Andre
Goessel, Detlef Reschke, Lea Steder, Lennart Trelle (DESY,
Hamburg), Wolfgang Carl Albert Hillert (University of Hamburg,
Hamburg)

Abstract Magnetic flux trapped in the Niobium bulk
material of superconducting radio frequency (SRF)
cavities degrades their quality factor and theaccelerating gradient. The sensitivity for flux trapping is
mainly determined by the treatment and the geometryof the cavity as well as the Niobium grain size and orientation. To potentially improve the flux expulsion characteristics of
SRF cavities and hence the efficiency of future accelerator facilities, further studies of the trapping behavior are essential.
For this purpose a magnetometric mapping system to monitor the magnetic flux along the outer cavity surface of 1.3 GHz
TESLA-Type single-cell SRF cavities has been developed and is currently in the commissioning phase at DESY. Contrary
to similar approaches, this system digitizes the sensor signals already inside of the cryostat to extensively reduce thenumber of required cable feedthroughs. Furthermore, the signal-to-noise ratio and consequently the measuring sensitivity
can be enhanced by shorter analog signal lines, less thermal noise and the Mu-metal shielding of the cryostat. In thisSUSPMF107

contribution the design and first performance test results of the mapping system are presented.

PEALD SIS Studies for SRF Cavities
Abstract Recent technological advances and material
Authors : Isabel González Díaz-Palacio, Robert Blick, Wolfgang

treatments have pushed Nb SRF cavities to theirCarl Albert Hillert, Andreas Stierle, Robert Zierold (University

maximum RF performance. A novel approach forof Hamburg, Hamburg), Arno Jeromin (DESY Nanolab,

overcoming this limitation, which takes advantage ofHamburg), Thomas Keller (DESY, Hamburg), Marc Wenskat

RF field only penetrates into the superconductor at a

(DESY, Hamburg; University of Hamburg, Hamburg)

certain distance called London penetration depth, isnano- structuring multilayers with PEALD(plasma-enhanced atomic layer deposition). SIS (superconductor-insulator-superconductor) multilayers provide magnetic
screening of the bulk Nb cavity, increasing the field at which the vortex penetration starts, and higher quality factor. ALD
is closely related to chemical vapor deposition and bases on sequential self-limit gas-solid surface reactions facilitating
conformal coatings with sub-nm precision even on complex substrates such as the interior of a cavity. As a preliminary
study for SIS SRF cavities, we investigated the AlN- NbTiN/NbN multilayers grown by PEALD. Different compositions,
thicknesses, and post-deposition thermal treatments have been investigated. The characterization results of

SUSPMF108

superconducting properties, elemental composition, crystallinity, and cross-section are shown in this contribution.

HOM Coupler Design and Optimization for the FCC-ee W Working Point
Authors : Sosoho-Abasi Udongwo, Ursula van Rienen, Shahnam
Zadeh (Rostock University, Rostock), Rama Calaga (CERN,
Meyrin)Abstract The Future Circular electron-positron Collider(FCC-ee) is planned to operate with beam energies
from 45.6 to 182.5 GeV and beam currents from 5.4
to 1390 mA. The purpose is to study the propertiesof the Z-, W- and Higgs boson and the top and anti- top quarks in four operation points. The beam current of 147 mA ofthe W working point requires particular care to string damp HOMs. This paper proposes 2-cell 400 MHz SRF cavities
with improved damping as an alternative to the baseline 4-cell cavities for this working point. The resulting impedanceof the HOM-damped cavity is then calculated and compared with the impedance budget.

SUSPMF109

IPAC’22

Combined In-Situ QEXAFS and XRD Investigations on Nb-Treatments in N2
Gas-atmospheres at Elevated Temperatures
Authors : Patrick Rothweiler, Franz Eckelt, Dirk
Lützenkirchen-Hecht, Sebastian Paripsa, Lukas Voß (Universityof Wuppertal, Wuppertal)

Abstract Thin polycrystalline Nb metal foils were treatedin N2 gas atmospheres at elevated temperatures of
900 °C up to 1200 °C. A combination of transmission
mode Quick X-ray absorption spectroscopy (QEXAFS)
at the Nb-K-edge and X-ray diffraction (XRD) used inparallel were used to investigate changes in the atomic short and long-range structure of the bulk Nb-material in- situ.
A dedicated high-vacuum heating cell with a base pressure of 10^(-6) mbar was used to perform the heat treatments undervacuum and nitrogen gas atmosphere. The treatments typically included (i) a preheating at 900 °C under high-vacuum,(ii) a treatment in 3 mbar nitrogen gas at the desired temperature and (iii) a cooldown to room temperature under vacuum
conditions. The QEXAFS and XRD data were collected in parallel during the entire process with a time resolution of 4s. While the samples treated at 900 °C show the typical N-uptake to the octahedral interstitial sites, the samples treatedat higher temperatures show the growth of distinct niobium nitride phases. The results will be discussed in more details

SUSPMF110

during the conference.

Analysis of Low RRR SRF Cavities
Authors : Katrina Howard, Young-Kee Kim (University of
Chicago, Chicago, Illinois), Daniel Bafia, Anna Grassellino(Fermilab, Batavia, Illinois)

Abstract Recent findings in the superconducting
radio-frequency (SRF) community have shown that
introducing certain impurities into high-purity niobium
can improve quality factors and accelerating gradients.
Success has been found in nitrogen-doping, infusion of

the native oxide into the niobium surface, and thin films of alternate superconductors atop a niobium bulk cavity. We question
why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity
profile of niobium with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low
RRR cavities so that the mechanism of recent impurity-based improvements can be better understood and improved upon.
We have found behavioral similarities between low RRR cavities and to high RRR cavities that are weakly nitrogen-doped.
Additionally, we performed surface treatments such as low temperature baking and nitrogen-doping on low RRR cavities
to evaluate how the intentional addition of more impurities to the RF layer affects performance. The results of this study
have the potential to unlock a new understanding on SRF materials.

SUSPMF111

IPAC’22

CVD Nb3Sn-on-Copper SRF Accelerator Cavities
Authors : Gabriel Gaitan, Peter Nitcholas Koufalis (Cornell
University (CLASSE), Ithaca, New York), Matthias Liepe (Cornell
University,Ithaca, New York; Cornell University (CLASSE),
Ithaca, New York), Victor Arrieta, Shawn Rex McNeal (Ultramet,
Pacoima, California)

Abstract Nb3Sn is the most promising alternative
material for achieving superior performance inSuperconducting Radio-Frequency (SRF) cavities,
outstripping the conventional Nb cavities now used inaccelerators. Chemical vapor deposition (CVD) is analternative to the predominantly used vapor-diffusionbased Nb3Sn growth technique and it might allow

reaching superior RF performance at reduced cost. Ultramet is an industry leader in the manufacture of refractory metal
and ceramic components by CVD. In collaboration with Cornell University and supported through DOE SBIR awards,
Ultramet has developed CVD processes and CVD reactor designs for coating of SRF cavities with Nb and Nb3Sn thinfilms. In this paper, we present our latest work on CVD Nb3Sn-on-copper SRF cavities, including detailed RF performance

SUSPMF112

test results from two 1.3 GHz SRF cavities.

Status Update on Cornell’s SRF Compact Conduction Cooled Cryomodule
Authors : Neil Anthony Stilin, Adam Holic, Matthias Liepe, Tim
O’Connell, James Sears, Valery D. Shemelin, Jessica Turco(Cornell University (CLASSE), Ithaca, New York)

Abstract A new frontier in Superconducting RF (SRF)
development is increasing the accessibility of SRF
technology to small-scale accelerator operations which
are used in various industrial or research applications.
This is made possible by using commercial cryocoolers

as a cooling source, which removes the need for expensive liquid cryogenics and their supporting infrastructure. Cornell
University is currently developing a new cryomodule based on a conduction cooling scheme. This cryomodule will use twopulse tube cryocoolers in place of liquid cryogenics in order to cool the system. A new 1.3 GHz cavity has been designedwith a set of four niobium rings welded at the equator and irises which allow for a direct thermal link between the cavity andcryocooler cold heads. The cavity will use two coaxial RF input couplers capable of delivering up to 100 kW total RF power for
high-current beam operation. This coupler design was modified from the Cornell ERL injector couplers, including simplifications

SUSPMF113

such as removing the cold RF window and most outer bellows, while retaining inner bellows for adjustable coupling.

Next Generation SRF Cavities at Cornell University
Authors : Nicole Verboncoeur, Matthias Liepe, Thomas Oseroff,
Liana Shpani, Zeming Sun (Cornell University (CLASSE),
Ithaca, New York)

Abstract Our goal is to develop new materials andprotocols for the growth and preparation of thin-film
and layered superconductors for next generation SRF
cavities with higher performance for future accelerators.
We are working primarily with Nb3Sn to achieve thisgoal, as well as other materials which aim to optimize the RF field penetration layer of the cavity. This contribution gives
a general update on our most recent cavity test results. A deeper insight into RF loss distribution and dynamics during
cavity testing is gained using a new global high- speed temperature mapping system (T-Map).

SUSPMF114

IPAC’22

Magnetic Field Mapping of 1.3 GHz Superconducting Radio Frequency
Niobium Cavities
Authors : Ishwari Prasad Parajuli, Alexander Gurevich (ODU,
Norfolk, Virginia), Gianluigi Ciovati, Jean Roger Delayen (JLab,
Newport News, Virginia; ODU, Norfolk, Virginia)

Abstract Niobium is the material of choice to build
superconducting radio frequency (SRF) cavities, which
are fundamental building blocks of modern particle
accelerators. These cavities require a cryogenic
cool-down to ~2 - 4 K for optimum performance

minimizing RF losses on the inner cavity surface. However, temperature-independent residual losses in SRF cavities cannot
be prevented entirely. One of the significant contributor to residual losses is trapped magnetic flux. The flux trapping
mechanism depends on different factors, such as surface preparations and cool-down conditions. We have developed
a diagnostic magnetic field scanning system (MFSS) using Hall probes and anisotropic magneto-resistance sensors to
study the spatial distribution of trapped flux in 1.3 GHz single-cell cavities. The first result from this newly commissioned
system revealed that the trapped flux on the cavity surface might redistribute with increasing RF power. The MFSS wasSUSPMF115

also able to capture significant magnetic field enhancement at specific cavity locations after a quench.

Design Study of High Efficiency Klystron for CEPC LINAC
Authors : Zhandong Zhang (IHEP, Beijing; UCAS,
Beijing;Université Paris- Saclay, CNRS/IN2P3, IJCLab, Orsay),
Munawar Iqbal (IHEP, ), Yunlong Chi, Dong Dong, Guoxi Pei,
Shengchang Wang, Ouzheng Xiao, Zusheng Zhou (IHEP,
Beijing), Shu Zhang (IHEP, Beijing; UCAS, Beijing)

Abstract The injector linear accelerator (LINAC) for
the CEPC requires a higher efficiency klystron with
80MW output power than S-band 65MW pulsed klystroncurrently operated on BEPCII LINAC to reduce energy
consumption and cost. The efficiency is expected to
improve from the currently observed 42% to more than
55% and output power will be improved from 65MW

to more than 80MW with same operation voltage. In this paper, BAC bunching mechanism is applied for klystron efficiency
improvement. The optimization of the gun and solenoid parameters is completed in 2-D code DGUN and 3-D code CST.
The preliminary optimization of the cavity parameters is also completed in 1-D disk model based AJDISK code and will
be further checked by 2-D EMSYS code and 3-D CST code. Finally, new klystron prototype will be fabricated in Chinesecompany after design parameters are determined.

SUSPMF116

IPAC’22Ferrite Specification for the Mu2e 300 kHz and 4.4 MHz AC Dipole Magnets
Authors : Keegan Harrig, Eric Prebys (UCD, Davis, California),
Luciano Elementi, Chris C. Jensen, Howard Pfeffer, Dean Alan
Still, Iouri Terechkine, Steven J. Werkema, Mayling Wong
(Fermilab, Batavia, Illinois)

Abstract The Mu2e experiment at Fermilab will measure
the rate for neutrinoless-conversion of negative muons
into electrons with never-before-seen precision. This
experiment will use a pulsed 8 GeV proton beam withpulses separated by 1.7 µs. To suppress beam induced
backgrounds to this process, a set of dipoles operating

at 300 kHz and 4.4 MHz have been developed that will reduce the fraction of out-of-time protons at the level of 1E-10
or less. Selection of magnetic ferrite material for construction must be carefully considered given the high repetition rateand duty cycle that can lead to excess heating in conventional magnetic material. A model of the electromagnetic andthermal properties of candidate ferrite materials has been constructed. Magnetic permeability, inductance, and power
loss were measured at the two operating frequencies in toroidal ferrite samples as well as in the ferrites from which
prototype magnets were built. Additionally, the outgassing rates of the ferrite material was measured to determine vacuum
compatibility. The outcome of this work is a detailed specification of the electrical and mechanical details of the ferrite

SUSPMF117

material required for this application.

Non Linear Phenomena Studies in High-Gradient RF Technology for
Hadrontherapy at IFIC
Authors : Pablo Martinez-Reviriego, Cesar Blanch Gutierrez,
Daniel Esperante Pereira, Juan Fuster, Nuria Fuster-Martinez,
Benito Gimeno, Daniel Gonzalez-Iglesias, Pablo Martín-Luna(IFIC, Valencia)

Abstract High gradient accelerating cavities are oneof the main research lines in the development ofcompact linear colliders. However, the operation ofsuch cavities is currently limited by non-linear effects
that are intensified at high electric fields, such as darkcurrents and radiation emission or RF breakdowns.

A new normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application(v=0.38c) designed and constructed at CERN is being tested at IFIC. In this poster, we present experimental measurements
and simulation results on breakdown analysis and dark current and radiation studies, in order to improve our understandingin such effects. The final objective consists of studying the viability of using this techniques in linear accelerators forhadrontherapy treatments in hospitals.

SUSPMF118

IPAC’22

Radiation Load Studies for the FCC-ee Positron Source with aSuperconducting Matching Device
Authors : Barbara Humann (TU Vienna, Wien; CERN, Meyrin),
Andrea Latina, Yongke Zhao (CERN, Geneva), Anton Lechner(CERN, Meyrin), Bernhard Auchmann, Jaap Kosse (PSI, Villigen
PSI), Iryna Chaikovska, Salim Ogur (Université Paris-Saclay,
CNRS/IN2P3, IJCLab, Orsay)

Abstract For an electron-positron collider like FCC-ee,
the production of positrons plays a crucial role. Oneof the design options considered for the FCC-ee
positron source employs a superconducting solenoid
made of HTS coils as an adiabatic matching device.
The solenoid, which is placed around the production
target, is needed to capture positrons before they

can be accelerated in a linear accelerator. A superconducting solenoid yields a higher peak field than a conventional-normal
conducting magnetic flux concentrator, therefore increasing the achievable positron yield. In order to achieve an acceptable
positron production, the considered target is made of tungsten-rhenium, which gives also a significant flux of un-wanted
secondary particles, that in turn could generate a too large radiation load on the superconducting coils. In this study, we
assess the feasibility of such a positron source by studying the heat load and long- term radiation damage in the
superconducting matching device and surrounding structures. Results are presented for different geometric configurations

SUSPMF119

of the superconducting matching device, considering different drive beams energies (6 GeV and 20 GeV electrons).

Spallation Target Optimization for ADS by Monte Carlo Transport Codes
Authors : Mustafa Mumyapan (SKKU, Suwon)

Abstract Accelerator Driven Systems are advanced
systems for the use of Thorium as fuel, aiming
to reduce nuclear waste through transmutation.

The spallation target, which is responsible for producing neutrons, is one of the main parts of the ADS system. In thisresearch, neutronic parameters of spallation targets consisting of several materials LBE, Mercury, Lead, Mercury on thecylindrical, box, and conic shapes using Monte Carlo codes (FLUKA, PHITS, MCNPX) was investigated. Energy Depositionand spallation neutron yield of spallation target with different shapes and dimensions have been calculated to optimizationof the target. According to the results, the neutron yield values from MCNPX and PHITS are similar and it’s close to theexperimental result. On the other hand, the error rate of the values in FLUKA is higher.

SUSPMF120

IPAC’22

Proposal of a VHEE Linac for FLASH radiotherapy
Authors : Lucia Giuliano, Fabio Bosco, Daniele De Arcangelis,Luca Ficcadenti, Daniele Francescone, Gaia Franciosini,
Mauro Migliorati, Luigi Palumbo, Vincenzo Patera (Sapienza
University of Rome, Rome), Maria Giuseppina Bisogni, Fabio
Di Martino, Jake Harold Pensavalle (INFN-Pisa, Pisa), David
Alesini, Alessandro Gallo, Alessandro Vannozzi (INFN/LNF,
Frascati), Giuseppe A. Pablo Cirrone, Giacomo Cuttone,
Giuseppe Torrisi (INFN/LNS, Catania), Vincent Favaudon,
Annalisa Patriarca (Institut Curie- Centre de Protonthérapied’Orsay, Orsay), Sophie Heinrich (Institut Curie, Orsay),
Mostafa Behtouei, Bruno Spataro (LNF- INFN, Frascati),Andrea Mostacci (LNF-INFN, Frascati; Sapienza Universityof Rome, Rome)

Abstract Translation of electron FLASH radiotherapy
in clinical practice requires the use of high energy accelerators to treat deep tumours and Very High Electron
Energy (VHEE) could represent a valid technique toachieve this goal. In this sce- nario, a VHEE FLASH
linac is under study at the University La Sapienza ofRome (Italy) in collaboration with the Italian Institutefor Nuclear Research (INFN) and the Curie Insti- tute
(France). Here we present the preliminary results ofa compact C-band system aiming to reach an highaccelerating gradient and an high pulse current
necessary to deliver high dose per pulse andultra-high dose rate required for FLASH effect.
We propose a system composed of a low energy highcurrent injector linac followed by a modular section of high accelerating gradient structures. CST code is used to define
the required LINAC¿s RF parameters and beam dynamics simulations are performed using T-Step, ASTRA and GPT

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tracking codes.

Post-Acceleration of Laser Driven Ion Beams Using Slow Wave Structures
Authors : Yuze Li, Hao Cheng, Dongyu Li, Chen Lin, Minjian
Wu, Xueqing Yan, Yang Yan, Tong Yang (PKU, Beijing)

Abstract Significant progress has been made inlaser-driven ion acceleration*. The laser energy
is first absorbed by electrons. Charge separation
can produce acceleration field with TV/m gradient,

generating protons with cut off energy up to ~80 MeV** in TNSA mechanism. However, the energy conversion efficiency
is relatively low (0.05-5%), due to electrons motion produced EMPs. A method was put forward to post-acceleratelaser-driven beams by reutilization of the EMPs energy***. A coil attached to the target acted as a slow wave structure
which synchronized the EMP with protons. The traveling field of EMP can further accelerate and focus ions. Since thedispersive nature of helical coil, the electric wave form is constantly changing****. we present a modified slow wave structure. Theoretical models are built to verify the validity of this improvement
scheme. The dispersion relation show this structure is free of dispersion. This work has been verified using PIC simulations.
The waveform remains unaltered, which means the acceleration path can be made longer. Through this method the protonenergy is hopeful to exceed 100 MeV in high power PW laser and the efficiency can be further raised.

SUSPMF122

IPAC’22Development of Magnetic Harmonics Measurement System for Small
Aperture Magnets
Authors : Jongmo Hwang, Jungbae Bahng (Korea University
Sejong Campus, Sejong), Eun-San Kim (KUS, Sejong)

Abstract Storage ring has been improved to achieve
high brightness of x- ray light source by making beam
size and beam emittance smaller and enlarging thebeam intensity. To achieve requirements such as a small

beam emittance, the magnets need to have a larger magnetic field gradient and complex function with small aperture size.
Since the complex structure and small beam size accompany with large errors in beam dynamics by high order field distortionof the magnets, it is important to measure the harmonics of the magnet in order to measure and improve it. Traditional fieldmeasurement methods such as hall probe and rotating loop have difficulty in measuring the harmonics of a magnet witha small aperture due to restrictions that physical size of the hall sensor and loop-card respectively.
We developed Single Stretched Wire (SSW) method for the magnetic field measurement method on a small aperturemagnet, in particular harmonics of the magnet. The system consists of a thin wire, accurate actuator system, and voltmeter.

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We describe the development of the SSW system and the result of the performance test by using our system in this paper.

CFD Studies of the Convective Heat Transfer Coefficients and Pressure Drops
in Geometries Applied to Water Cooling Channels of the Crotch Absorbersof ALBA Synchrotron Light Source
Authors : Stefania Grozavu, Gustavo Adolfo Raush (ESEIAAT,
Terrassa), Joan Josep Casas, Carles Colldelram, Marcos
Quispe (ALBA- CELLS Synchrotron, Cerdanyola del Vallès)

Abstract Currently, the storage ring vacuum chambersof ALBA are protected by 156 crotch absorbers madeof copper and Glidcop. After more than 10 years ofoperation as a third-generation light source, the ALBA
II project arises, aiming to transform this infrastructure

into a fourth-generation synchrotron. This introduces new challenges in terms of the thermal and mechanical design of the
future absorbers. The absorbers’ cooling channels consist of a set of 8-mm-diameter holes parallel to each other drilledin the body of the absorbers. In each hole, there is a 6x1 mm stainless steel concentric inner tube coiled in helical wires,
whose aim is to improve the heat transfer. The convective heat transfer coefficients used for the original design of theabsorbers come from experimental correlations from the literature, which are limited to a few geometric variations. In thiswork, CFD studies of the convective heat transfer coefficients and pressure drops in the known cooling channels arecarriedout, as well as new proposed variations of the geometry that have not been reported in the literature. This information will
be useful for the sizing of the new absorbers for the ALBA II project.

SUSPMF124

IPAC’22

Design of a Proton Therapy Eye Treatment Nozzle Using a Cylindrical Beam
Stopping Device for Enhanced Dose Rate Performances
Authors : Eustache Gnacadja, Nicolas Pauly, EliottRamoisiaux, Robin Tesse, Marion Vanwelde (ULB, Bruxelles),Cédric Hernalsteens (CERN, Meyrin; ULB, Bruxelles)

Abstract Proton therapy is a well established treatment
method for ocular cancerous diseases. General-purpose
multi-room systems which comprise eye-treatment
beamlines must be thoroughly optimized to achieve
the performances of fully dedicated systems in termsof depth-dose distal fall-off, lateral penumbra, and dose rate. For eye-treatment beamlines, the dose rate is one of themost critical clinical performances, as it directly defines the delivery time of a given treatment session. This delivery timemust be kept as low as possible to reduce uncertainties due to undesired patient movement. We propose an alternative
design of the Ion Beam Applications (IBA) Proteus Plus (P+) eye treatment beamline, which combines a beam-stopping
device with the already existing scattering features of the beamline. The design is modelled with Beam Delivery SIMulation(BDSIM), a Geant4- based particle tracking and beam-matter interactions Monte- Carlo code, to demonstrate that it
increases the maximum achievable dose rate by up to a factor 3 compared to the baseline configuration. An in-depth

SUSPMF125

study of the system is performed and the resulting dosimetric properties are discussed in detail.

Slow Extraction Modelling for NIMMS Hadron Therapy Synchrotrons
Authors : Rebecca Louise Taylor (CERN, Geneva), Jaroslaw
Pasternak (Imperial College of Science and Technology,
London), Elena Benedetto, Mariusz Sapinski (SEEIIST, Geneva)

Abstract The Next Ion Medical Machine Study (NIMMS)
is an umbrella R&D programme for CERN accelerator
technologies targeting advanced accelerator options
for proton and light ion therapy. In collaboration with
the European program HITRIplus, one area of study

is slow extraction, required to deliver a uniform beam spill for radiotherapy treatment. Several techniques use the third- orderresonance to extract hadrons; these include betatron core driven extraction, radiofrequency knock-out, and quadrupole
sweeping. Flexible simulations tools using these techniques were prepared and initially benchmarked with results fromthe literature that used the Proton-Ion Medical Machine Study (PIMMS) design - as utilized by CNAO and MedAustron.
The limits of the current PIMMS design were then pushed to evaluate its compatibility to deliver >10x higher intensity ion

SUSPMF126

beams, and using faster extraction regimes.

Design of the 590mev Proton Beam Line for the Proposed TATTOOS Isotope
Production Target at PSI
Authors : Marco Hartmann, Daniela Candida Kiselev, Davide
Reggiani, Mike Seidel, Jochem Snuverink, Hui Zhang (PSI,
Villigen PSI)

Abstract IMPACT (Isotope and Muon Production with
Advanced Cyclotron and Target Technologies) is a
proposed initiative envisaged for the high-intensity
proton accelerator facility (HIPA) at the Paul Scherrer
Institute (PSI). As part of IMPACT, a radioisotope

target station, TATTOOS (Targeted Alpha Tumour Therapy and Other Oncological Solutions) will allow the productionof terbium radionuclides for therapeutic and diagnostic purposes. The proposed TATTOOS beamline and target will belocated near the UCN (Ultra Cold Neutron source) target area, branching off from the main UCN beamline. In particular,
the beamline is intended to operate at a beam intensity of 100 µA, requiring a continuous splitting of the main beam via
an electrostatic splitter. Realistic beam loss simulations to verify safe operation have been performed and optimised using
Beam Delivery Simulation (BDSIM), a Geant4 based tool enabling the simulation of beam transportation through magnets
and particle passage through the accelerator. In this study, beam profiles, beam transmission and power deposits are
generated and studied.

SUSPMF127

IPAC’22

A Novel Method of Emittance Matching to Increase Beam Transmission for
Cyclotron Based Proton Therapy Facilities
Authors : Vivek Maradia (PSI, Villigen PSI; ETH, Zurich),
Antony John Lomax, David Meer, Serena Psoroulas, Jacobus
Maarten Schippers, Damien Charles Weber (PSI, Villigen PSI)

Abstract In proton therapy, high dose rates can reduce
treatment delivery times, allowing for efficient mitigationof tumor motion and increased patient throughput. With
cyclotrons, however, high dose rates are difficult toachieve for low-energies as, typically, the emittanceafter the degrader is matched in both transversal planes using circular collimators, which does not provide an optimal
matching to the acceptance of the following beamline. Transmission can however be substantially improved by transporting
maximum acceptable emittances in both orthogonal planes, but at the cost of gantry angle-dependent beam shapes at
isocenter. Here we demonstrate that equal emittances in both planes can be recovered at the gantry entrance using a thin
scattering foil, thus ensuring gantry angle-independent beam shapes at the isocenter. We demonstrate experimentallythat low-energy beam transmission can be increased by a factor of 3 using this approach compared to the currently usedbeam optics, whilst gantry angle-independent beam shapes are preserved. We expect that this universal approach could

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also bring a similar transmission improvement in other cyclotron-based proton therapy facilities.

Monte Carlo Simulation of Electron Beam in Phantom Water for Radiotherapy
Application
Authors : Pittaya Apiwattanakul (Chiang Mai University,
Chiang Mai), Sakhorn Rimjaem (Chiang Mai University, Chiang
Mai; ThEP Center, Bangkok)

Abstract Radiotherapy (RT) is an effective treatmentthat can control the growth of cancer cells. Thereis a hypothesis suggests that secondary electrons
with an energy of a few eV produced from RT play
an important role on cancer¿s DNA strand break.

In this study, the Monte Carlo simulation of electron beam irradiation in phantom water is performed to investigate theproduction of low- energy electrons. Electron beams produced from an RF linac are used in this study. The accelerator
can generate the electron beam with adjustable energy of up to 4 MeV and adjustable repetition rate of up to 200 Hz.
With these properties, the electron dose can be varied. We used ASTRA program to simulate the beam dynamics in theaccelerator and GEANT4 program for studying interactions of electrons in water. The energy of electrons decreases from
MeV scale to keV-eV scale as they travel in the water. From simulations, the dose distribution and depth in phantom water
were obtained for the electron dose of 1, 3, 5, 10, 25, and 50 Gy. Further study on effect of low- energy electron beamwith these dose values on cancer DNAs will be performed with GEANT4-DNA simulation.

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IPAC’22

Performance Study of the NIMMS Superconducting Compact Synchrotron
for Ion Therapy with Strongly Curved Magnets
Authors : Hannah Norman, Robert Appleby (UMAN,
Manchester), Mikko Karppinen (CERN, Geneva), Maurizio
Vretenar (CERN, Meyrin), Hywel Owen (Cockcroft Institute,
Warrington, Cheshire; STFC/DL/ASTeC, Daresbury,
Warrington, Cheshire), Elena Benedetto (SEEIIST, Geneva;
TERA, Novara; CERN, Meyrin), Suzanne L. Sheehy (The
University of Melbourne, Melbourne, Victoria)

Abstract Delivery of heavy, charged particle therapy
currently utilises normal conducting magnet based
accelerators, predominantly synchrotrons. For the
future generation of clinical facilities, the footprint ofsuch accelerators needs to be reduced while adopting
beam intensities above 1 × 1010 particles per spill
for more efficient, effective treatment. The Next Ion
Medical Machine Study (NIMMS) is investigating thefeasibility of a compact (27m circumference) superconducting synchrotron, based on 90- degree alternating-gradient,canted-cosine-theta (CCT) magnets to meet these criteria. The understanding of the impact of higher order field multipolesof these magnets on the beam dynamics of the ring is crucial to the effective optimisation of the design and to assess its
performance for its suitability for treatment. In this paper, we analyse the electromagnetic model of a superconducting
magnet to extract its non-linear components and fringe fields. Preliminary assessment of the effect of such nonlinearities

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is performed using MADX/PTC. Further scope, involving cross-referencing with other particle tracking codes, is discussed.

Ripple Pattern Formation on Silicon Carbide Surfaces by Low-Energy
Ion-Beam Erosion
Authors : Divya Gupta, Sanjeev Aggarwal (Kurukshetra
University, Kurukshetra), Gajigatte Umapathy (IUAC, New
Delhi), Rahul Singhal (Malviya Institute of Technology, Jaipur)

Abstract A versatile air insulated high current medium
energy 200 kV Ion Accelerator has been runningsuccessfully at Ion Beam Centre, Kurukshetra University,
India for carrying out multifarious experiments inmaterial science and surface physics. Ion beam induced

structures on the surfaces of semiconductors have potential applications in photonics, magnetic devices, photovoltaics,
and surface-wetting tailoring etc. In this regard, silicon carbide (SiC) is a fascinating wide-band gap semiconductor for
high-temperature, high-power and high- frequency applications. In the present work, fabrication of self- organized ripple
patterns is carried out on the SiC surfaces using 80 keV Ar+ ions for different fluences at oblique incidence of 500.
Studies demonstrate that ripple wavelength and amplitude, ordering and homogeneity of these patterns vary non-linearlywith argon ion fluence. The ripples tend to align themselves parallel to the projection of the ion beam direction. The evolutionof such surface structures is explained with the help of existing formalisms of coupling between surface topography andpreferential sputtering.

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IPAC’22

Design and Parameterization of Electron Beam Irradiation System for Natural
Rubber Vulcanization
Authors : Pitch Wongkummoon, Nopadol Kangrang, Sakhorn
Rimjaem, Jatuporn Saisut, Chitrlada Thongbai (Chiang Mai
University, Chiang Mai), Michael W. Rhodes (IST, Chiang Mai)

Abstract Electron beam irradiation is a process tomodify or improve the properties of materials with lesschemical residue. In natural rubber vulcanization, aproper electron absorbed dose is about 50-150 kGy.
In this study, the experimental station is designed toinvestigate the deposition of the electron beam in natural rubber. Electron beams generated from an RF linac are usedin this study. This accelerator can generate the beam with energies in the range of 1-4 MeV and an adjustable repetition
rate of up to 200 Hz. We can optimize these parameters to maximize the throughput and uniformity of electron dose in
the vulcanization. The simulation results from GEANT4 were used to narrow down the appropriate parameters in theexperiment. In the early stage of the study, water was used as a sample instead of natural rubber. The dose distribution
was obtained by placing a B3 film dosimeter under a water chamber. The water depth was varied from 0.5 to 2.0 cm. The
simulation results provide the dose distribution to compare with the experimental results. In a further study, the beam

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irradiation in natural rubber with these optimal parameters and vulcanization tests will be performed.

Design of Radiation Shielding for the PBP-CMU Electron Linac Laboratory
Authors : Phanthip Jaikaew (Chiang Mai University, ChiangMai), Sakhorn Rimjaem (Chiang Mai University, Chiang Mai;
ThEP Center, Bangkok)

Abstract At the PBP-CMU Electron Linac Laboratory,
we aim to generate the coherent terahertz radiation andmid-infrared free-electron lasers. The accelerator system
can produce electron beam with maximum energy
of up to 25 MeV. During the accelerator operation,

it is possible to generate bremsstrahlung photons and neutrons when electrons hit beam dump or vacuum chambers. The
radiation shielding is therefore essentially important. The study of radiation generation and design of radiation shielding
are conducted and presented in this work. To investigate the radiation dose rate and obtain the design of radiation shielding,the geometry of our accelerator hall was implemented into the Monte-Carlo simulation program GEANT4. The study results
including radiation dose map and design of local shielding for the specific parts of the system will be addressed in thiscontribution. With this design the radiation dose rate outside the accelerator hall is as small as 1 uSv/year. From the results,
we purpose the shielding design to control the dose rate to the safety limit as stated by IAEA regulation.

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IPAC’22

Design of Linac Based Neutron Source
Authors : Nirupama Upadhyay, Sajeev Sakai Chacko (Universityof Mumbai, Mumbai), Abhay Deshpande, Tanuja Sushant
Dixit, Ramamoorthy Krishnan (SAMEER, Mumbai)

Abstract Neutron sources are of great utility for various
applications, especially in the fields of nuclear medicine,
nuclear energy and imaging. At SAMEER, we havedesigned a linear electron accelerator based neutron
source via photo-neutron generation.

The accelerator is a 15 MeV linac with both photon and electron mode and is capable of delivering high beam current
to achieve beam power of 1 to 2 kW. Efforts are in place to achieve further higher beam powers. 15 MeV electrons are
incident on a bremsstrahlung target followed by a secondary target to achieve neutrons. To further optimize and enhance
the neutron yield, backing material is provided. In this paper, we present the simulation of (e, g) and (g, n) processes using
the Monte Carlo code FLUKA. The optimization of Tungsten as the convertor target whereas of the Beryllium as theneutron target is discussed in detail. We have explored various backing materials in order to optimize the total neutron
yield as well as the thermal neutron yield. The simulation results have been considered for the finalisation of all material

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parameters for the set-up of this neutron source activity.

High Transport Efficiency and Tunable Beamline for Laser Plasma Accelerator
Authors : Yang Yan, Hao Cheng, Dongyu Li, Yuze Li, Chen
Lin, Minjian Wu, Xueqing Yan, Tong Yang, Zhong Xi Yuan,
Kun Zhu (PKU, Beijing)

Abstract A beamline is required to focus proton beams
produced by laser plasma accelerator to high charge
density spots for practical applications. The Compact
LAser Plasma Accelerator (CLAPA) coupled with animage-relaying beamline has been built at Peking

University*. While the collection section of this beamline is an electromagnetic quadrupole (EMQ) triplet with certain aperture,
more than 71% of the protons are lost in the inlet end face or vacuum tube wall of triplet due to their own divergenceangles**. Here we show the development of a high transport efficiency and tunable beamline by adding two permanent
magnet quadrupoles (PMQs) in front of the triplet. PMQs with magnetic field strengths of 200 and 120T/m respectively havelarger collection angle of about ±70mrad. Genetic algorithm (GA) is applied to design the system with goal of the highest
transport efficiency. As a result, by monitoring PMQs’ relative positions and EMQs’ currents, the focusing energy is able tobe adjusted ranging from 2 to 10 MeV, and the transport efficiency is about twice as high as only collected by EMQ triple.

IPAC’22

STUDENT POSTERSESSION GUIDE

June 12-17, 2022